Porsche 911 Oil Cooler Upgrade

If you are driving a Pre 1983 Porsche 911 with the stock oil trombone cooler, where the local summer temperature might exceed 80 – 85 degrees in the summer,  you will find yourself with oil temperature readings hovering at a blistering 250 to 270 degrees F.   Even if you are not in a warm climate area, simple idling, such as in a traffic jam will have oil temps climb beyond belief.   So owners that have cars on the track also know very well the issues of extreme oil temperatures for your ending.   The Pre 1983 Porsche 911 ideal temperature is best at around 230 degrees F as cooler car temperature won’t cause oil viscosity breakdown and thus engine parts do not wear down as fast. Could it be that you are wondering about getting your Porsche 911 an Oil Cooler Upgrade?

The fact is that for warm days and /or hard driving, your stock trombone cooler is not enough to keep your car cool. Therefore the following line of action needs to be removing the entire older stock trombone line and replacing it with brand new lines, thermostat and oil cooler. The task isn’t particularly difficult, you just need to know some plumbing and under the passenger side wheel well fabrication skills to pull it off.

You must remember, that having the oil cooler alone is not going to keep your oil temperature at lower levels.  We all know that when driving, oil gets hot and there isn’t anything you are going to be able to do about it other than shutting off the car and letting it sit to cool down.  However, if you happen to be using the BAT / MOCAL radiator 44 fin vs. 6 – 24 copper tube solution, cold air drawing in rushes the flooded hot oil, with fresh cold air.   The cold air brings down the boiling oil temp and returns it back to the oil tank.  This trick, along with fittings and thermostat will better arm your car against that heated oil which causes viscosity breakdown.

A common and proven solution includes replacing a right side horn grill with a plastic air scoop that allows air to flow in from the outside flushing the radiator as the car is moving.  Often, an electric fan combined with the radiator might be used to further blow cool air quickly rushing oil temperature to a more manageable levels of extreme hard driving.  These two solutions working together act well to keep the oil cool.

For the later model of Porsche (1983), oil cooling was a known issue.  They provided an “indentation” between the right bumper and valance for air scooping.  This lip indentation only appears on the one side.

For racing, where maybe an headlight is not used, it is common to removal of the right headlight and replacing it with a large funnel scoop could also be a source for getting colder air to an oil cooler.  Often the wing well will have a grill over what used to be the headlight.   Having such an upgrade often makes a great solution in completing the car.

Other creative ways to reduce oil temperature is having finned hard line to and from the oil tank.  The concept behind the fins, is that more surface area touches the pipes and therefore adds to drawing the heat away before and after it goes to the oil cooler.   Secondary larger finned pipes have been seen and used to further add to pulling more heat out away from the oil lines.

Keep in mind that having such lines will require you to use just about the number of quarts required for a 911.  But you need to check it.   Also know two that when changing oil out, you need to make sure all for this draining of the oil lines.    Never the less always avoid overfill the oil tank.  Reducing or preventing oil from getting red hot is always the main goal.


Porsche 934 Turbo changed a lot of hands.

Chassis Num: 930 670 0161

One of my most favorites competition cars is the  Porsche Type 934/5 Competition Coupe.   It was the 28th 934/5 example produced by Porsche, delivering lightening fast performance. Belgian business owners , Losch and Nicholas Kobb, ordered from Porsche and bought new this yellow livery car specific to offer both owner and driver duties.   Performing very well, this car was raced at Zolder, then only after one performance was sold.  Hans Christian Jurgensen of Flensburg, Germany bought the car in 1976, and modified it slightly.  The car then saw the racing circuit for three whole years often finishing in the top three places.

Porsche Racing Enthusiast Armando Gonzales of Puerto Rico bought this car in 1979.  Almost immediately, after purchase in 1979, sent the car to Chuck Gaa of Atlanta Georgie.  New modifications included a high mounted gearbox to reduce drive shaft angularity.   The car also offered stiffer roll-cage structure for occupant safety.  By 1982, the car raced at LeMans and several other international circuits.    It was then in 1982 that another Porsche collector Kikos Fonseca saw the car and had to own it.

Kikos Fosenca’s raced the car in several important IMSA and South American events. At some point during this time period, updates were made, converting it to a 935-style fiberglass nose and tail with air scoop penetrating the rear screen to feed air to the massive multi fin intercooler. The time and energy to own this car must have been intense.  Still a very fast car, it wasn’t hard to sell auction in 1988.

In 1990, the car was registered for street and freeway uses for four years.   It was owned and well cared for till the owner exchanged for a Ferrari 275 GTB/4.   The ex-Ferrari owner had restoration ambitions that never happened.  Instead, it was  Jim Torres of Burbank Coachworks who eventually fully restored it in 1999. Upon completion, it was brought to venues such as Daytona and Willow Springs with screaming lap times.

In 2008, this Type 934/5 Competition Coupe was brought to the ‘Quail Lodge, A Sale of Exceptional Motorcars and Automobilia‘ presented by Bonhams Auction where it was estimated to sell for $375,000 – 425,000.

The car is still for sale, with an estimated price around $425,000.

Ayrton Senna owned a Porsche 911 and drove the backroads of Rio.

Ayrton Senna 911

Not just another Porsche owner, Ayrton Senna, (b. March 21 1960 – d. May 1, 1994) must have enjoyed driving the Brazilian city streets and back roads in his Arctic White 80’s Porsche 911.

He probably was just as hypnotized by the sweeping past his windshield trees covered in a purple and white flowers, nationally acclaimed Ipê-amarelo (Tecoma chrysostricha).  With his top down he could glance up and watch swatches of color blur past.

So what must have made this person tick to drive so accurately?   He must have had fast reaction times or a sense of memory and flow.  If you think about it, one could drive a track based on visual and then intuition and finally memory.   The better safer combination would be visual + intuition + memory forcing reaction.   Other cars would just be there to slow someone down.   I think it was Senna’s particular gift to get on a track, with full memorization of all curves, sways, lines and then with some intuition and vision could go faster than someone else using just vision.     Vision alone would be a reaction time, but if you had the patterns memorized, you could react faster.   As long as you were not distracted, you wouldn’t worry about vision as much because, you already had everything else dialed in.  Senna would be able to put himself into a track layout and knowing the expectation of his car, could drive it faster than anyone else.

In Rio De Janerio, his hometown would be loaded with hundreds of miles of roads and streets he would drive around.   He would have memorized locations of every cross walk, one ways and terrain to maximize his smoothness in his 911.  A racetrack, undoubtedly shorter and much less distractions, would be a far safer place for him to maximize acceleration.

From the University of Brazil, he could get on B.R. 101 and coast drive west 50 miles to Mangaratiba and decide to take the uphill mountain road highway RJ-149 40 miles to Pirai‘ and from there swoop back to Rio, using the winding curved ‘Rod. Pres Durtra’ highway BR 116 through Belford Roxo and back to the University in Rio.      In the distance described, there would have changes in terrain, straightaways, curves, swoops and weaving traffic… just about every condition imaginable.

Enjoy the new movie SENNA, if you haven’t seen it.    Have a great week.

The skyrocketing values of the Porsche 911

In 1973 I was in the 9th grade, and it was then my conservative father was eyeballing german engineering. Some of you might have remembered the campaign by Porsche stating their 911 RS as “the driving machine”. At that time my Dad was pushing fifty, and probably saw that $10,000 beast as expensive. At that time, median prices of homes still lingered at $35,000 while a full fledged new car would be hard pressed to touch $5000.00. So like for so many people in the same boat, practicality outweighed investments and he bought something else.
Just last month, a Porsche 911 RS sold for $350,000 plus!

The question is, is this kind of investment potential still possible? There are now four models of Porsche that still have it’s potential of strongly sliding into that oblivion of skyrocketing costs. There has been a significant rise in prices for the 928, 944, and 914. Tuners and restoration shops are becoming really good about correcting stock and problematic issues with higher reliability aftermarket products. furthermore the driving factor is still impressive by today’s standard. It’s starting to make lots of sense on that keeping your 944 turbo and alternating it to exceed the expectations of new model cars. Just recently there was even customer that bought a used 86 944 turbo one is now forever sorting out quirks that will find himself with a very nice car. These kinds of stories are not isolated, because like this trend is dictating there is even another report of a guy that bought a roller 914 for $750 and with $45,000 turned it into an absolute jewel complete with the unusual six cylinder option. The key being he knew where and how to setup upgrades.
Just this month, the 1980 Porsche 911 SC took a nice $6000 increase in value, setting low values at $17,600 and high values at a whopping $23,500. “there is a chance as 911 become even more desirable and the cost of ownership becoming offset with the fact you don’t need a $15k-30k analysis and diagnosis computer to figure out if your fan belt is loose”. We can see these cars reaching $45,000 or more with the huge plus that these kinds of cars will be the next strongest contender to own for it’s fun value and investment. “we know guys that own and daily drive these cars for very little money, only because they can research help on the Internet“. Some mechanic shops are seeing it more and more that it is common to find customers that want help with the most crucial parts and will do the rest themselves. All 911 cars between 1966-1989 are becoming more and more harder to find.
So if you are in any market to own, start checking it out so you don’t end up “with something else”.
Incidentally, the 928 is a fantastic machine, and if you have never seen one, you would not be surprised it could hit the $45,000 price range too.

Porsche Sportomatic available for the 911 and “pre-1972” 914/6

Using a vacuüm operated diaphragm clutch and a 4 speed trans-axle the Sportomatic was a Porsche rave in 1976.   As the driver, you would get to run your 911 without ever having to shift.   Still, if you looked inside, you would clearly see that there a stick shift between a driver and passenger. 

The Porsche Sportomatic is surprisingly similar to the early 4 speed manual transmission, with also having on the reverse a sliding gear to make a parking lock arrangement.

Using the vacuum servo arrangement, gear changing occurs automatically by having the clutch move in an opposite direction than your traditional manual clutch shifting.  To drive using the Sportomatic is actually very nice, and very easy.  All you is jump in, then stick in the key.  Upon starting, the familiar Porsche engine sounds completely 911.  The stick shift is completely 911 as well, in which all you do is shift into gear, and off you go. 

There is ‘P’ Park, ‘R’ Reverse, and then ‘L’ Low and four (4) ‘D’ Drives.  There is no clutch pedal to press.

Porsche’s biggest reason for even providing this option was for a growing youth of US drivers that just did not know or want to fool with a clutch.  Even now, less and less car manufacturers are providing clutches and the problem will become an issue as manual transmission sales continue to dwindle to the hardest core shifter only car drivers, like myself.     What was more remarkable was Porsche designers were completely was aware exactly how none sportsmanlike having a traditional automatic transmission was in the sports car world.    Reinventing a special breed of sports cars, what Porsche did was then to make a “Sportomatic transmission”, a kind of semi automatic shifter that the Porsche driver would need to control.   This kind of transmission wasn’t causing the driver to need to manipulate foot to clutch to shifting timing.   This also got rid of some very notorious bad habits, like the infamous over-rev.  You bet.  Since this kind of transmission is not full automatic, it requires the driver to think of shifting gears like in a regular 4 speed.  Start rolling in first gear… maybe get up to rolling speed in second and then third and fourth but the sound of the engine.  There was never a fifth gear in those days.

In this sense, the driver would then place all their attention driving a 4 speed without the foot clutch.  

Here at A. Bauer Porsche, we see them occasionally.   Most of them had ended up getting damaged, and then it turns out they changed out to the five speed manual transmission.  To change them out you will have to do some modifications to get them installed.   Others, should one be lucky to get parts, can get them repaired with factory specifications.

The Sportomatic transmission option, (cost adding almost was not factory isolated option for the 911, but was also provided on five experimental pre 1972 914/6 as well.    Amazing!!!

If you happen to have a Sportomatic Porsche, make sure to keep it because its rare, and more importantly don’t convert it to manual transmission.

For Diplomats – Porsche Panamera 4S

When I learned that IMF Chief Strauss Kahn personal car was a black Porsche Panamera S, I couldn’t help to think of a more perfect car for quick getaways from hotel rooms to airports.

This premium class four door – four seat sports car is everything the rave.  Built for racetrack or parked at executive valet lots this 3.6L V6 is nothing less than for the flaunting playboy millionaire.  Leather seats holds all occupants safely with room to fill out important documents and signing using expensive pens.  The chauffeur would have full control with having trust worthy all wheel drive.  He could accelerate it from 0-60mph in less than 5.2 seconds to get away from pesky paparazzi who only have slow slug moving motor-scooters.

Unique is the Direct Fuel Injection (DFI) and VarioCam Plus to get this 16/24 mpg car all the way to 400 hp.

The French diplomat Chief Strauss Kahn almost made the clean getaway but should have bought the even faster Panamera Turbo that would clean Border and slipped away back to France.     I mean, he must of knew someone was chasing him by getting to listen to the news blotter on his uncompromising sound system by Burmester.

Now if would simply understand that Gov. Arnold Schwarzenegger had bought himself a more important looking Panamera, rather than his 911 Turbo, he may have found himself free of similar and drove himself somewhere far.

What makes the Porsche 911 a Porsche 911RS?

The Porsche 911RS is one of the strongest outlaw contender of the modern sports car.  But obviously, as many must ask, what then is the RS?  What was its purpose?

RS is coined for “Racing Sport” and… if you wanted to be even more technical, it is better name is “Rennsport“.

A philosophy derived from Lotus innovator Colin Chapman who deducted that the more you decrease weight of a car, and do nothing else, you should get significant performance.  You should also get better handling and because the car is lighter, quicker braking.   This thinking was opposite to what was happening to cars from the 60’s.  All those cars were trying to be fatter, big engine performance, massive spoilers, huge grinding brakes and full tilt suspension.

Porsche’s earlier models such as the “356” was equally nimble and light as any Lotus, but like the remainder of the trend, started to get heavier and beefy.  Porsche Designers then realized that the small frame of the 356 wasn’t going to allow larger engines.  In the redesign, the 911 was born, those P-cars too found it irresistible to make more powerful.  It did not take very long to then wondered what would happen if the cars skimmed off weight with powerful engines.

Born was the 1973 Carrera 2.7RS.  Porsche’s Engineering Director Ernst Fuhrmann, knew he had something worthy of production and coined the “RS” designation.  He took the 2.4L engine, fattened it up while lightening the weight of the car.  The removal of weight wasn’t actually unique, a matter of fact, it had already been a ten year old concept practiced by Italian Porsche Tuner, Carlo Abarth, where he took a 356 Carrera and converted it to be an unbeatable winner.     Name the Abarth Carrera GTL, he altered his cars to be specific for race purposes.

A “tested theory” on an already fabulous 1973 911S,  the special attention for Rennsport race car development had already proved worthy.  So much so, Porsche produced 500 of them for general sales.

Expect the factory modifications to be included in the Carrera RS, and you will have 210hp@6300rpm and torque of 255@5100rmp.   Not only you get a very loud popping racing car, but you get hat lifting, white knuckle excitement at the seat of your pants.   Fuhrmann snagged racing technology from the very successful Porsche 917, and found using a larger 90mm Nikasil-coated aluminum cylinders which adaptations guaranteed hard, low friction surfaces.  So successful of quality all Porsche engines retained versions of “Niksil” technology forever from that point on.

It was then this savvy Engineering Director’s wish to lighten the load.    Carefully studied materials, structural shaping, plus other quickly asserted engineering measured equally effective by today’s standards change the Porsche 911S.   Thinner steel, thinner glass, larger wheels with light weight flares and a practical down force duck-tail were all employed into the car.

To better handle lighter weight and more power, suspension changes were altered to use stiffer Koni dampers,  with stiffer anti-roll bars and uprated motor mountings.  All bushings were also made to better lock the car’s wild tendencies to bay.

While some Porsche 911RS (M471) were pure race cars with that “hard teeth jarring ride, back riveting stack of bone crushing nerve pinching” performance.   It was the hope that privately used race tracks were ribbon smooth, unlike bumpy city streets and so you can gain in suspension.   In comparison to the 911S cousin, the interior was stripped of all comforts of home.   Manual windows, reduced soundproofing, no rear passenger seats, the clock deleted, and no passenger sun visor.  The engine-compartment duck-tail lid and unique looking RS front bumpers were made of sculpted lightweight fiberglass.   Simply put, about 220 pounds stripped away.    Racers would then find other ways to knock off even more weight by opting to remove and replace 40 lbs of rear tail lights for a lighter RS types, interior rugs for plastic mats, lighter door handles, and even drilling out steel plates to make them lighter.   Door pockets were deleted, as so were the interior handles, replaced by leather straps ingeniously acting as door latches.  Center board was removed, and shifter and all that heater stuff deleted.

A Porsche RS Touring (M472) had a softer ride for those that actually wanted to use their cars more than just a track.   With the interior exactly like the 911S, and with steel bumpers and engine lid, these would prove to be available for anyone who could afford it, to use.

In 1973, the Porsche 911S would sell for $10,065, while the RS Carrera version would run $10,895.   Today, you would need around $200,000 to touch one.

      REUNION IV  p o r s c h e

End of story for outlaws?  Not exactly.   It is important to note that Porsche at that very time, also in 1973 created 109 more cars with the brand new 3.0L engine.    Don’t hold you’re breath if you are ever going to see one, but if you do take a photo of it and send it me.  Maybe you can let me use your time machine?

Go back to 1973 and trade this DeLorean for an RS.

Higher Octane Fuel – Is it worth it?

If you have an electric car, this post is not for you.   We will talk about how to effectively benefit from solar glare in another post.

For the rest of you, 0ne biggest questions faced on the road today, with the ever-growing rising fuel prices, is picking out the right fuel for your car.  We we decide in pulling up to any particular gas station, we are given with at least three choices of fuel grades.    Each significantly different, and of course with different prices.  The decision is that nowadays, you will find an almost a 2% percent difference in prices between REGULAR, MID GRADE, and HIGH TEST.

Differences between brand name gas (Shell, Mobil, Arco) and cheap gas (Alaska, Rotten Robbies, Costco) will also reflect the price of your full tank.  We also see differences of prices between stations is competing with other stations at a regular intersection, or if the station that might be outside of town forty miles of another station.

We all want to know if using higher octane improves miles per gallon, provide more power and better for your car?  In order to answer these questions you need to understand what and how fuel is defined.

All fuels have an Octane rating that measures proportions of iso-octane to heptane in a fuel.   That rated proportion relates to how much energy it takes to ignite that fuel.

It is important to recognize that the higher that octane number, the more energy it takes to ignite that measurement of fuel.

Chemical engineers constantly run tests on developing a proportion iso-octane to heptane levels to best obtain an octane rating.

High Octane does not give your car better gas mileage. This is because that octane levels is in proportion on how much energy it takes to ignite, NOT the energy the fuel produces.   Unless your car is explicitly designed to run on high octane gas, it will not give your car better gas mileage.   At the same time, using High Octane will not improve horsepower either.

It is important to recognize that it is fairly rare to find cars the require use of high octane fuel!  Note too that Higher Octane will not magically clean the insides of your engine!  It will not clean out deposits or fix “piston rings”.

If your car happens to requires high octane gas, such as a 2011 Porsche 911 Carrera Speedster (check your manual) then and only then you will want your car to run high octane fuel.

The main reason is that octane ratings has everything to do with the characteristics of compression and ignition timing of the engine.

You will notice some engines to some cars will have an 11:1 ratio vs other cars that have compression/ignition timing ratios of 6.5:1.   Knowing this compression/ignition timing ratio, will tell you which kind of fuel your car will need to run efficiently!

For example, the 6.5:1 compression/timing ratio found in a Porsche 356 Roadster will mean that it can ignite fuel very much differently than what might be found in a compression/timing ratio of 11.7:1 found in a Porsche 911 GT2/GT3.   This relationship between compression and ignition timing is your assurance that fuel will ignite with a specific needed amount.   You don’t want the wrong fuel octane level, because of course, ignite will be wrong and the car will run crappy.

What is interesting is that the compression/timing ration relationship has very little to do with the fact the car might be a track car such as the Porsche 935 Coupe that only has a compression/timing ratio of 6.5:1.  Does that mean the owners of a 935 will probably be looking for 86 octane and it will run happiest being leaded?   No, this is because he has additional adjustments in his Engine Control Unit (ECU) or Engine Control Module (ECM) that handles fuel, air and ignition timings electronically.   What about your street car?  If it had the same compression/timing ratio of 6.5:1 like the Porsche 935 Coupe, does that mean you will look for 86 octane.   Maybe.. you need to check your owners manual.   There is specifies what is the stock setting of your automobile.   If you happen to have your car chipped or that the ECU has been modified to meet a different compression / intake ration, then you will need to consult with those adjustments.   Some ECUs will know what your fuel might be igniting at and recalculate spark, air, timing, etc.    Knowing this key aspect of fuel is a great way to not spend more on gas than you need too for your tank.  You will not being doing your car any favors by purchasing better gasoline than it needs.

Back in the early 80’s there was this huge campaign regarding engine “pinging”.   Pinging, a more technical term than knocking was a sign that gas was not igniting when it should.   If you can imagine, a chamber (inside the engine) about to connect air-gas-ignite to push a piston, missing out on and not having that relationship of compression and ignition. That chamber fails to perform a duty efficiently and hurts the chamber, not giving you a better ride.

You will notice a reduction in power and your gas mileage will be horribly low.   Using a higher octane will then reduce that pinging noise.   If you are running, say that 356 and the manual says nothing about the car’s ability to use a higher octane, something needs to be adjusted such as timing and spark plugs.  Do not assume you can fix the problem with the simply using higher juice.    This goes back to the concept that relates energy needed to ignite the gas.   If the gas is igniting too easily, therefore igniting before it is suppose too, there will causes of engine knocking or pinging.   Of course then you will notice lower gas mileage and power zapping efficiency.

For your information… one might describe the pinging or knocking sounds a lot like shaking small rocks in a coke can.  Think of this knocking or pinging as detonation vs. ignition.  Think of knocking of an explosion and not a silent fizzle of a burn.   That detonation is rather harsh and you should well notice it.

You must look at your manual to know which gas is optimized for your car.  The car’s ECU/DMI or if carburetors; will completely dictate how the gas will interact with the listed spark plugs, cylinder wall chambers, air intake, exhaust, timing…all of that.  So back to the guy with the race car Porsche 935; if you remember his low compression/intake ratio (6.5:1), that he might have his car set up for a different ignite.   He is in a race car, which means he also has a 24/7 mechanic that tweeks everything related to maximizing power.  Air, electrical, fuel, spark.. all of that is focused on going fast (150mph fast); not sitting in traffic, a 20mph cruise around lake or barely getting above 70mph on the freeway.   Because he is in a race car, the car will need to have very different driving conditions that requires him possibly the highest in octane, as much as 117.     Even more on the extreme, the formula racers running alcohol or even funny cars that run on pure jet fuel would have settings that vary as well.

So take a look at your manual and determine what is the fuel you should be using, and don’t buy higher octane than what is required.  Doing so chances in damaging your engine, not making it better.


For turbos there is effective compression ratio (ECR) and static compression ratio (SCR).  Effective compression ratio changes with the air pressure from the turbo.  All  1976 – 1989 930 have low static compression (At least for 87-79 usa cars it is between 6.5:1 or 6.7:1, but effective compression is computed as: ECR= SCR * sq rt [1+ (boost/1)].  Given the primitive electronics were used in those cars, and not computerized its important to use high octane fuel.

Here are some compression ratios that might be helpful for you.  Look in your manual for exact octane needs.

1948 Porsche 356 – Compression Ratio = 6.5:1

1950 – 1954 Porsche 356 – Compression Ratio = 7.5:1

1956-1959 Porsche 356A 1600S – Compression Ratio = 8.5:1

1960-1963 Porsche 356B Super 90 Roadster – Compression Ratio = 9.0:1

1963-1964 Porsche 356C Carrera 2000 Coupe – Compression Ratio = 9.8:1

1964-1967 Porsche 911 Coupe / Targa – Compression Ratio = 9.0:1

1965-1968 Porsche 912 Coupe / Targa – Compression Ratio = 9.3:1

1972-1973 Porsche 911 Carrera RS 2.7 – Compression Ratio = 8.3:1

1976-1989 Porsche 930 – Compression Ration = 6.5:1 or 6.7:1

1979-1983 Porsche 928S – Compression Ratio = 10.0:1

1983-1989 Porsche 911 Carrera 3.2 = Compression Ratio – 10.3:1

1985-1991 Porsche 944 Turbo = Compression Ratio – 8.0:1

1987-1988 Porsche 959 = Compression Ratio 8.3:1

1989-1993 Porsche 911 Carrera 2 & 4 = Compression Ratio 11.3:1

1991 Porsche Turbo = Compression Ratio 7.0:1

1992-1995 Porsche 968 = Compression Ratio 11.0:1

1993-1997 Porsche 911 Carrera (993) = Compression Ratio 11.3:1

1996-current Porsche Boxster / Boxster S = Compression Ratio 11.0:1

1997-current Porsche 911 (996) = Compression Ratio 10.4:1

2001 Porsche Carrera 4S = Compression Ratio 11.3:1

1999-current Porsche 911 Turbo (996) = Compression Ratio 9.4:1

2003 – current Porsche 911   /GT3 = Compression Ratio 11.7:1

2002 – current Porsche Cayenne = Compression Ratio 9.5:1

2003 Porsche Carrera GT = Compression Ratio 12.0:1


More reading on this subject can be found on http://www.rennsportsystems.com/2a.html


All of the experts we spoke with say the most important thing for consumers is to choose one brand of gas and stick with it. Changing from brand to brand can lead to those deposit buildups that can cause problems for your car, including reduced gas mileage.

Paragon Laboratories

BP 87 Octane ... 17.2 milligrams per 100 milliliters
BP 93 Octane ... 26.4 milligrams per 100 milliliters

Citgo 87 Octane ... 6.0 milligrams per 100 milliliters
Citgo 93 Octane ... 9.4 milligrams per 100 milliliters 

Exxon 87 Octane ... 20.0 milligrams per 100 milliliters
Exxon 93 Octane ... 21.2 milligrams per 100 millilitersPilot 87 Octane ... 5.8 milligrams per 100 milliliters
Pilot 92 Octane ... 8.8 milligrams per 100 milliliters
Shell 87 Octane ... 16.2 milligrams per 100 milliliters
Shell 93 Octane... 31.0 milligrams per 100 milliliters