Prem gas?

Yes. yes you do. all the other GURUs will beat me up if I say it's okay to put 91 in there...high treason!

The 2000 E Class Mercedes 4.3L V8 has a compression ratio of 11.2:1 and that and the 3.2L V6 both call for regular 87...according to Edmunds, anyway

I would at least run a couple of tanks of both grades of fuel. Keep notes on your gallons used and mileage. Use the fuel that results in the best MPG's.

Can't argue with that logic. Well put. I was just doing some refresher reading on octane/compression ratios/flash points....been a long time since chemistry 101.... and things like that because of another question I ran across, some fellow was claiming a bad oil ring will lower the octane of the fuel. I couldn't find the words, yet, to explain it will NOT actually change the octane, but sure, oil seeping by the ring(s) will change the volatility, but the lower the octane the less stable the gas is, and a higher octane resists pre detonation, am I making any sense at all? Coffee is called for....

High compression engines...say arbitrarily....above about 12:1 should have 91... or at least 89....I read Mazda was producing an engine scheduled for the 2014 model year with a compression ratio of 14.5:1, a $2 million Bugatti 16 cylinder 1,100HP with four turbo's and a mind boggling 0 to 60 in 2.5 seconds runs 9.0:1 compression ratio..I need to do more reading

9.9 in the 1/4 mile...and that is not the 1,000 foot dragstrip now used, but a full quarter mile....252MPH...and street legal .....I think I will drop one of these in my Corolla..

I could buy 190 Corollas like mine for the price of that motor. Which should I do?

Yep true. My 1.8L 130HP 16valve scoots. I have to drive up a 7% grade regularly, and pass (most) all I need to. It's a 2 lane divided and sometimes trucks will decide to pass one another...one in slow lane going 9 mph and one passing in fast lane going 9.25mph and it takes it 3..4..5 miles to pass. No joke here. then when it finally gets over and 900 cars are stacked up I get past most. On rare occasions the CHP will nab them for doing that but not often enough

If a CHP would hang out in that area he could write enough tickets to fund his time X10. Or she. Sorry. Or put a damper on it. It is the closest I ever get to road rage..and I am as mellow and laid back as a guy gets. The do get a salute from me though..one digit salute

I've felt the rage, HWY 29 thru American Canyon, posted speedlimit is 60, and recently they imposed some "punishment lights" for their local commerce (walmart)....everyone drivin' it acts like their tail is on fire and wants to get all up in your stuff unless you're ten over-....and of course burn up many sets of brakes screetching to the red light not 150 ft ahead...uuugh-

Sorry Pal Didn't mean to dig up old nightmare experience~~~~~~~~~~~`

I never do more that 75 on freeway, mostly 65~70 and on side streets that's not my you are describing bud..really....

I only meant I get back to 65 in less time than most

You ALWAYS lookout. you've taken your driver's ed class...you know when it's okay...as a cab driver found a million ways of skirtin' the man-

imagine if we all flew autogyros. the skies would be clobbered with them winds would send the group into itself, but you wouldn't have to wait in stop and stop traffic, because autogyros cannot stop.

Central Calif Northeast of Bakersfield, a little over 5,200ft in the foothills of Sierra Nevada

George Jetson would be ashamed

well now, my friend break out the umbrella 'cause today or tomorrow you're getting our rainstorm,(is it isn't all used up). Sounds like a great place to fly radio controlled planes in- nice and remote-

ooo just hit me 5200 ft. of course you'll see some snow...don't get socked in!...at least you'll have all your guru buddies to keep you company. Did we answer the question? did he burn premium?...what saltines?

You should use Premium fuel, however, I have had several MB's and BMW's that run great on regular fuel. In theory you should have lower power and mileage - however, I have not really noticed that. The trick is to stick with 'real' gas such as Shell, Mobil, etc. You need to experiment - if you do not have any valve 'pinging' you are ok, otherwise stay with the higher octane.

bobkat, Right ON. All gasoline is not the same. Matter of fact right now, at least here in Calif, they are switching to "summer blend" and that is their excuse for gas being well over $4 right now, yesterday I had to pay $4.22 for regular

I used to be able to reduce pinging back in the old days when we could still adjust timing, back it off a degree or two, settle for the lowered idle speed, and keep driving---nowadays, make friends with your robot.

Come on, higher octane fuel is best for all vehicles, it burns cleaner inside the engine,(less carbon build-up), and lasts longer,(less fuel is needed for the necessary spark within the chamber. I have always used Premium fuel on all my rides. Better response too. Yes, all German vehicles 1990 and newer/performance vehicles, do require Premium fuel, because that's what the ECU is programmed for.

A good sour mash whiskey should have enough potency to do the job~

Higher octane means higher flash point. It needs a hotter spark and high compression to ignite properly. It is not BEST for ALL cars. It does not mean less fuel needed. It is a matter of temperature of ignition....that's why pinging can be solved by going to higher octane, it ignites at a higher temperature and won't pre~detonate. A gallon of 91 contains no more energy than a gallon of 87

I totally agree with DavidH25. A car (such as most GM & Ford's) that are designed to run on 87 Octane will not necessarily run any better on 89 or 91 or 93 Octane. The only "sure thing" is that you will spend way more money without a corresponding return on power or mileage increase. That being said - most BMW & Mercedes will run just fine on 89 Octane even though the manual says you must use 91 Octane. If you are a racer, than stick with 91 or 93 Octane. Modern engines will adjust for octane differences. As I mentioned in a previous post, stick with quality fuel - try to avoid the 'pump & go' off brands. The reason they are cheaper is because they contain less additives and are "older". Yes, gas does go stale with age.