Is supper gasoline really better for your car

I was having a conversation with my mother snd she sais that the grade of gas doesn’t matter for your car. I have a 1997 BMW and I want to know if it matters for my car and or for all types of cars

Is this gas you buy around dinnertime!!!

It varies depending on the car. Go by what the owners manual says. Chances are the engineers at BMW know more about your car than your mom does.

I conclude you/your mother thinks the money spent on preminum fuel is wasted. Is she saying “if you have money for preminum fuel you have money for something more important”.

Or is this strictly a technical discussion that has nothing to do with how you spend your money?

Beleive it or not we get many questions from people that want to use a fuel that is a cheaper price than the fuel the manufacture recommends. What I ask them to look at is how much they really will be saving. I realise that for some people saving $5.00 has more value than it does to me.

It is a bad idea for me a BMW trained tech (I admit I did not achieve master level) to say you can use a lower octane fuel than BMW recommends. The results probably won’t be as extreme as internal engine damage but there will be consequences.

I like breakfast gasoline much better than supper gasoline. It has a fruity taste.

I depends on what the owner’s manual says. If the owner’s manual says it is required, your mother is wrong.

I am willing to bet the owner’s manual says to use high octane gas.

The true experts for your car are the ones that wrote the owners’ manual.

If it says “premium recommended” then you can use regular with some compromise in performance and perhaps mileage.
If it says “premium required” then you should not use regular.

The subject is much debated, but there’s nobody on the planet that knows more about what your car hsould get than the manufacturer’s tech writers…who get their information from the design package.

Follow the manual (or the sticker in the filler door). Then use non-ethanol gas if you can.

I agree–as I usually do–with mountainbike’s excellent advice.

And, if your screen name is connected with the model of your BMW, and you do in fact drive a BMW M3, then you absolutely need to use premium gasoline (also known as “Ethyl” in some parts of the US, or “Super”).

If you are driving an M3 and you use regular grade gas, the massive repair bills that will result will really make you wish that you had opted to spend 20 cents more per gallon for premium gasoline.

Unless your mother has a degree in automotive engineering, plus a wealth of experience in engine design, I would suggest that you IGNORE her recommendations on fuel and other topics concerning your car.

The engine computer will probably be able to compensate if you put in lower octane than recommended. It will compensate by retarding the ignition timing when it detects spark knock. This will reduce your engine performance and probably fuel mileage as well, reducing much of the ‘benefit’ of buying cheap gas. If the engine computer can’t compensate fully, long term spark knock can lead to engine damage. On my car I can get away with filling up with a little lower octane every other fill up without consequences. If you can afford to maintain a Beemer, why not just spend the extra $1.60 or so a week that it costs to get the recommended fuel?

Do they still sell non-ethanol gas anywhere? In my region 10% is required everywhere.

Mom knows better:
If burning 87 octane in your car, when 91 octane is specified, will not harm the engine, and the performance degradation is not noticeable in typical driving, how much money can you save? The Energy Information Administration, U.S. Government Department of Energy, offers some figures for US gasoline retail prices (these are averages, all areas, all formulations). A year ago Regular was going for $2.982 a gallon and Premium was commanding $3.196 a gallon. The 21.4 cent difference delivered a 6.7 percent saving over Premium. This June 23, 2008, Regular extracted $4.079 from your wallet while Premium sucked up $4.312 for every gallon. The differential (23.3 cents) has grown slightly since 2007 but buying Regular is now only 5.4 percent cheaper than Premium. Since 5 percent is roughly the typical percentage of mileage decrease to be expected with the 87 octane fuel in a 91 octane engine, is there any savings at all?
Massive repair bills due to 87 octane in a maintenance hungry M3? LOL

“Do they still sell non-ethanol gas anywhere?”

It is legal almost everywhere in the USA. But only in low population areas. SoCal, the Central Valley, the Northeast Corridor, Chicago, St. Louis, DFW, and Houston are where it’s required.

In the E46 models with the S54 engine I’d believe it. Those engines were very finicky.

Check your owner’s manual. Chances are it will tell you that you can use lower octane, but it will reduce mileage and power (just a little), but why did you pay all the money you did on that car, only to dumb it down?

Then again, this is a chance to make mom feel good and tell her you are going to get regular from now on. It also can make you feel good because you are making mom feel good, WIN WIN.

Then once in a while get a tank of high test, see if you notice a difference (likely not)

If the car REQUIRES hi-test…then USE hi-test. If not you’ll see a decrease in performance and gas mileage…and in some cases a destroyed engine.

If the car requires no more then regular…then using hi-test is a waste of money.

The quality is the same in Premium gasoline, as in Reg’lar. Yes, the same. The difference is anti-knock properties.
The engine computer can’t adjust for conditions which are outside its range of control. AND, who said that adjustments, and compensations, will always work flawlessly? Who? Risk a damaged engine for a few pennies? Choice.

I looked on Edmunds at the 1997 BMW M3 and it says- premium unleaded fuel REQUIRED.

Manufacturers do not specify these things unless they have to. Of course the car would appeal to more people if it did not REQUIRE premium fuel so why limit your audience unless it is absolutely necessary?

Obviously, it cannot adjust enough to compensate for the lower octane rating and this means the engine will likely be perpetually pinging. If that doesn’t result in a large bill when the bearings are shot from all the abuse, the owner would be very lucky indeed.

Your LOL should stand for Lots Of Luck!


Thank you for confirming my recollection of the octane requirements for an M3 Beemer.

Why, oh why, oh why would someone buy a high-performance car and then try to cheap out on the gas?

I had always heard that breakfast gasoline was better.

No problem and I’m jealous of your power of recollection!

I went to a house party once and the people had obviously over extended themselves. It was a sprawling mansion in a great neighborhood. Unfortunately, the house was essentially bare with no furnishings and you had to wear a coat since they couldn’t afford to heat the place. This was no housewarming party, they had been in the place for a couple of years by then. Keeping up with the Jones’ was more important than creature comforts, I suppose.

Some people buy things only because they like the way it looks, or how it makes them look, rather than for its intended purpose.