The UK uses a different formula for computing the octane ratings. You can't compare them straight across with the US ratings.

 

I know - and I appreciate that fact.

Not sure why the rating generally in Europe is much different.

As far as I knew - its better enviromentally to have a lower octane number providing it is mixed with ethanol like in CA and many other states in the US.

 

Lower octane gas is actually better than premium grade. Lots of folks don't realize it. That's why they think they get something (HP) by using premium when their engine doesn't need it.

Regular gas is more volatile than premium. Premium burns slower. Hotter running modern engines and hotter running performance engines need to use premium because regular gas ignites too fast. That's what "pinging" is. The gas ignites from engine heat instead of waiting for the spark plug to spark. It ignites before the piston passes TDC so the piston wants to push the crankshaft backwards.

You probably know all of this. I'm just rambling.

 

Keep Rambling Dude,

Your Right, and I agree, so many peeps miss the point when it comes to men and motors!!

 

Well i would not say that the AVERAGE luxury car driver would not know this but i hope that people on here trying to fix there own cars would.

 

You got me thinking, if premium is less flamable-which it is- one would think there are lots of cheap additives that would retard the efficiency of a substance to ignite: you know, like water does so well. So, why isn't there some liquid I can buy by the gallons, real cheap, that a few ounces in the tank will make "premium" or less flamable fuel?

BTW, why does the word inflamable mean "highly flamable", when it contains the prefix in-, which almost always mean "not".

 

Go see what's in octane booster.

It's probably something boring like the root word is inflame.

 

Most Americans drive more than 12,000 miles per year and with prices being as high as they are, the difference between regular and premium is now more like 25-30 cents per gallon. If you drive about 20 miles each way for work (I drive closer to 25 each way), that is 40 miles per weekday (assuming you don't run any errands before or after work which involves more driving). Assuming you go shopping, visit friends/family/whatever on Saturday or Sunday, you probably are driving a comparable distance. There are 365 days or 52 weeks per year. Let say weekdays equal 200 miles (5 x [20+20]) and any potential after work / weekend activity equals another 100 miles. That is about 300 miles per week or about 15,600 miles per year. For simplicity let's say is 15000. Lets also say the average car gets 20 mpg overall, which is probably a little generous or right on the money. That's 750 gallons per year. If the difference is 25-30 cents per gallon, the difference in costs are between about $190 and $225 per year, or about $4 per week, which isn't much.

Since any car requiring premium fuel only requires 91 octane, what you really could do -- to save a whopping $2 or so a week -- is fill up your tank with about half premium (93) and half regular (87). Actually, if you did a real 50/50 fill, you would average out at 90 octane, so you still are a bit low, but the ECU should easily be able to adjust (on '96 and later cars) for the 1 octane deficit.

I currently have an '05 C55 and an '02 C320 wagon. Believe it or not, before I made the "big time", I had not one, not two, but three Ford Festivas in my life, each was bought for less than $1000. They were all great cars, ran on regular, and got between 30 and 40 mpg, depending on how bad I beat it. I'm looking for one on eBay right now as a way to address fuel costs, not playing with the fuel used in the '55.

 

I would certainly hope u dont.

 

Hi guys,
getting back to octane booster,
purchasing booster and pumping regular would exceed the costof just pumping 91+