tyro

Yes! Increased profits for the oil monopoly! :p

Buellwinkle

Actualy the "oil monopoly" as you put it does not profit from premium over regular, like I said the difference in refining costs is pennies, 2-3 cents at most and that's understandable. The value of premium over regular is controlled in the commodities market and not set by any single group or company. The large difference in prices between regular and premium is in the distribution and sale of that product, not the cartels. What's ironic in all this is that the pipeline cost of fuel, what one oil company charges another, is usually about 1 cent cheaper in No Cal than in So Cal, yet prices at the pump are considerably higher in No Cal over So Cal. It's just what No Cal people expect to pay so the stations charge it and pocket the extra profit. Then costs vary by location so I have to pay 25 more by my house than at work, the cost of living in a better neighborhood than I work in.

r_liebo

but Porsche just announced last year that their "premium fuel" cars all run just fine on regular. I've run 87, 89, 93 octane in my car at various times. I do seem notice a marginal difference in acceleration (but it may be the placebo effect), and my mileage goes from 19.6 to 19.7mpg, but not everytime I fill with premium (have heard the difference is much greater on the c230 engine, though). I am certainly no expert, but I doubt you will be doing any damage to your engine by using regular (automakers would be in big trouble if their cars fell apart due to regular gas), but you won't be optimizing performance, and you probably will be suffering a bit gas mileage wise (but not much).
I ran a varying mix like above on all my previous cars as well (except, ironically my Porsche), and never had a problem at all over several hundred thousand accumulated total miles.
Unlike some others on this board, I don't get offended that someone wants to save a few bucks at the pump with their Mercedes, so give it a shot, see what happens. If you don't notice a difference, you may want to stick with it.

MarcGetty

I can't say for sure about how much performance is gained by higher octane gas over lower octane gas, but I documented 50,000 miles of research on my 2002 C230 comparing octane rating to gas mileage.

91 octane definitely gets better gas mileage then 87 octane, and 93 octane definitely gets better gas mileage then 91 octane. However, the increase in gas mileage is not enough of an increase to make up for the increases in cost between each grade.

When driving long distances I *ALWAYS* get the highest octane available. The difference in range between a tank of 32 MPG fuel (512 miles) and 29 MPG fule (464 miles, 48 miles diffenrence) is substantial.

This is the difference between having to stop every 7 hours vs. 6 hours 20 minutes. When driving very long distances in a day:



higher octane, and the better fuel economy it provides can get you there faster by stopping for gas less.

-Marc

'81 VW Mk1 Scirocco Philadelphia, PA
'84 VW GTI Bunny Truck marc@getty.net
'02 MB C230 Kompressor AIM: DaMarcDaMarc

amdeutsch

No flame but I can burst that bubble real fast.
I run 100 Octane and get worse mileage than on 87. Performance is the same as 91. Except it doesn't have the same BTU content. Why am I doing it? Because I get a $1.50 per gallon one for one tax break from my state for running E85 alcohol fuel. My mileage is approx 25% less than using 91. But at the same time I only pay about $0.30 per gallon of gas after my tax break.

I know. I cheat.

MarcGetty

I never said that octatnes >93 were any better then 93. I only wrote how each octane increase between 87 and 93 octane gave me better fuel economy.

-Marc

Buellwinkle

I don't understand, you say you get more than a 10% benefit in fuel mileage between regular (29) and premium (32), and the price difference between the 2 fuels is usually less than 10%, at least around here, how is it not cost justified?

I would imagine that putting lower grade fuel in a V6 does not have the same performance penalty than in the Kompressor. Also, climate and altitude have a lot to do with a fuel's anti-knock capability. For example, if you live in Denver you can easily drop a grade and not notice. Also, if you live in a humid, cooler climate like the rain forests of southeast Alaska you can probably drop a grade. But in the southwest where it's hot and dry, you need all the 'tane you can get....

Guest0001

I think its BS myself. 89 and 91 are not too different from what ive been told. But i still put 91

elchinocache

in my slow *** car i notice a huge difference when there is 87 and when there is 93. My car feels like a real fat fat slow b!@#$ when i have 87 octane, but when i have 93 octane in there, its just a slow b!@#$

mctwin2kman

I just follow what the engineers that built the engine suggest. They know more than I do about engines! Although I do think it is funny that Lexus calls for mid grade and a turbo volvo engine calls for regular!!! How come Volvo can Turbo a car and still make it produce power while running on regular pump gas. My parents new S60 runs on regular and produces 205 HP....

r3v1ls

I've been filling up my car with Premium for the first year and a half... until my dad took to service the car. One of the guys, i think mechanics was surprise that we were putting premium into a leased car, considering that we have to give it back in a year n a half. So i'm just wondering what the rest of you guys put in your car. Personally if we owned the car, we would definitely put Premium only in it. From experience, the difference in performance is minimal. I currently fill it up with regular, and it's been running just fine, nothin out of the ordinary. I feel that the car is a bit faster wit Premium but that mite be just mental. I also thought that it wasn't too smart putting regular in a supercharged car, but everything has been running just fine...

akbro93704

You aren't going to damage the engine by putting regular gas in it, but it's best to always put what an engine requires for best performance and economy.The engine computer and knock sensors adjust timing to compensate for the low octane fuel, but the trade off is worse fuel economy and less horsepower, and in your case the supercharger boost is dialed down also. Since you get worse gas mileage using regular fuel versus premium, there's really no trade off because you'll be filling up more. The difference between a tank of regular and a tank of premium is probably about 3 or 4 dollars, so it won't hurt to use premium, what your car requires.

BabyBenz6spd

With my aggressive driving "Premium" is required~ :v (Consistant High RPM)

But seriously, I wouldn't use anything less than Premium on a supercharged car.

tuscanraider

87

I used to put super in, then I switched to reg. and saw absolulety no difference in performance. Oh yeah, and mine is a lease....

PsssTkiD

premium.

i never tried putting regular in my car. i dont want to take any risk. i follow my bible

ctC230K

93 or 91 and the price just went up to $2.44, ****ty

Brunelleschi

typically 91, but for some reason none of the gas stations in Tulsa have 91, so I use 93 there

polar240

Since gas is so friggin expensive in Canada, I've resorted to the good old 50%regular/50% water. Not good for the hp department but you do get a little more mileage. LOL

LaZyC230K

91, the gas price in LA here is 2.71 now, feel so great

xxbenzc230kxx

91.... and the price here in the bay area is $2.89 ... man almost 3 dollars for one freakn gallon.. hehe

MJ50

91

ctC230K

you dilute your gas with water? that must do wonders for your engine

Brunelleschi

ummm.....hmmmm

racee

My dealer and service techs say the factory recommends mid grade as I have had quite a few problems with carbon buildup and starting problems. It has worked great for me so far.

Deutscher_Wagen

91 is the highest I can get in Colorado, unless I drive for 100plus miles or go to the racetrack and get 105.

91 is going for about 2.13-ish here now... I would never put anything less than 91 in my car!