My dealership told me that I can switch off using premium and regular. I have heard that before but I have never tried regular gas in my car yet. (i have an 03 C240). I was wondering what all of you guys do and if there is a difference in performance when you use the regular.

 

There are as many opinions on this one as there are owners out there, so I'll give you mine as a car builder, hot rodder, engine builder, and Mercedes owner. Put premium in it and forget it. You bought a Mercedes. Enjoy it.

 

I saw a drop in gas mileage of at least 2 mpg (about 10-11%)using 87 vs. 93 octane. Also felt a drop in power when driving aggressively.
These cars are made to run fineon any gas (consider they're used in third world countries all over the word where gas standards are lacking).
It seems that what you wouldgain in saved gas money you would lose in mpg.

 

I have always put premium in mine. Honestly, it's only a $0.10 a gallon difference. Somewhere I remember someone calculating how much it would be after a year of average driving... I don't remember exactly how much but it was somewhere around $100.

RE: tabourj: Wouldn't the cars being used in 3rd world countries be different models though? Like trucks, etc? I can't imagine seeing an SL65 driving along in Uganda... Talk about income inequality[:@]. I would think that the trucks and vehicles made to be a little more rugged would be more lenient towards poor quality fuel.

 

I agree, its worth the extra, Im in the UK and pay for regular unleadedĀ£0.95pence, and Super = Ā£1.05 a Litre [:@]- yes thats over $2 US a Litre or $8 per US Gallon.

However, my C320 in combined inner city driving, averages 280 to 300miles per tankful on standard unleaded, and 320 to 330 miles on Super Unleaded= Shell V-Power.[8D]

In my view it works out the same price per mile as you get extra miles! and the car likes it better too!!

Happy motoring!!

 

I wish there was only a 10Ā¢ difference between regular and premium here around D.C. There is about 22Ā¢ difference. That adds up but not that much. At 19mpg, 45% highway, 55% city driving, 15000 annual miles and a fuel price of $ 3.11 per gallon for regular your yearly cost is $2455. Now compare to premium, At 19mpg, 45% highway, 55% city driving, 15000 annual miles and a fuel price of $ 3.33 per gallon for premium your yearly cost is $2629. Less than $200 difference. I found this information at fueleconomy.com

I say just put in the premium, your car will be happier, and you'll be happier with the performance..