I'm from the uk where we get a new fuel called optimax at 98.5 ron.

I just filled up with it in my c200k, was just wondering if it will do any harm 2 my engine ?

so far it feels a wee bit quicker.

What are ure opinions?

 

We have had Optimax in Canada for a few years. However I do recall reading that there was a problem due to some additive since removed that was eating up fuel sensors. I hope they removed this additive in the UK.

 

oh ****, now u tell me

 

Check this out for details. Question your petrol dealer about this.

http://www.thisdayonline.com/archive...0529bus08.html

 

In Germany Shell sells 99 RON Gas and the ADAC tests revealed that Shell gas is the cleanest compared to the other major manufactures...so I doubt it would harm your car, I used it exclusivly on my BMW 328i and it never caused a problem during the 65000 miles I drove it.

 

What is 98.5 RON in U.S. terms? I've used 100 U.S. Octane unleaded and didn't notice a thing except the $5/gallon dent in my wallet.

 

94.5 US octane. There is no need to buy anything higher than 91 US octane or 95 RON. Where I live we get 93 US for premium, 89 mid-grade and 87 regular.

 

I've never used anything but Optimax and have had no problems at all.

 

I use 91 to 93 octane. Antyhing higher is going to be waste of money. It won't harm your car.

How much are fuel prices up in UK?

 

98 RON is around 93 R+M. These engines are cal'd for 91 R+M according to the manual if I read it right. (not here in front of me to verify)

So even our 93 is overkill in theory but I buy it anyway (always some variance from between brands).

High octane fuels can actually hurt power w/o changing spark advance due to a slower burn rate. I have seen this on the dyno. (will not hurt the engine)

Octane is a measure of resistance to spontanious burning and Cetane is a measure of how easliy fuel burns spontaniously (Cetane is used for diesel fuel)

some good info here if your interested... http://www.prime-mover.org/Engines/G...es/octane.html

 

i'v tried pushing mine further and its a lot quicker and more responsive than before, it actually goes 2wards the redline far quicker, plus it sounds more meaner too