Do you always use "Premium Gas"?

[about6]

I have always used "Premium Gas" in any vehicle I drove. Even when gas prices topped $4 bucks! Have I just been conditioned or is there really an advantage for using the top shelf?

[cmzwirner]

Its only $4 more per fillup. Obviously!

[m2pc]

In my old 328is and current M3, yes. In my other cars, no.

[kornkid8600]

Yeah. If you run lesser gas in these cars they don't run as good. You'll get worse gas mileage too, enough to the point where you're almost saving nothing by going with the lower octane.

[ninjaman111]

yes

[KnudsonsM3]

yes

[raoke]

yes /thread

[GaTech]

Affirmative.

[MasterKwan]

In my old 328is and current M3, yes. In my other cars, no.

This, it's stupid to run higher octane fuel in vehicles that won't benefit from it. It does nothing to improve performance and will give you worse fuel economy.

So, the "Fit" gets piss gas from any station pumping it, and the M3 gets gas only from stations that I know are really pumping 93.

[shaeff]

This, it's stupid to run higher octane fuel in vehicles that won't benefit from it. It does nothing to improve performance and will give you worse fuel economy.


This. Use what fuel your motor was designed to run on. Using 93 octane in a car that clearly states 87 is just making your wallet lighter, and there is ZERO performance gain, despite what your butt-dyno tells you. That's called the Placebo effect.

Once you begin to modify the car, chip/tune, whatever, use what fuel the tuner suggests.

It always makes me LOL when I see people putting 93 into their 1992 Honda Civic with a fart can. Because Race Car.

[das borgen]

it s all the same gas from the same refineries....companies just put in different additives to get the octane rating up.............doesn t the sticker on the odo say 95 RON?

95 RON = 91 AKI....in the USA, gas stations publisj AKI numbers...........89-91 is fine.....but in actuality, any gas is fine as long as the engine doesn't knock

[ThreeD]

it s all the same gas from the same refineries....companies just put in different additives to get the octane rating up.............doesn t the sticker on the odo say 95 RON?

95 RON = 91 AKI....in the USA, gas stations publisj AKI numbers...........89-91 is fine.....but in actuality, any gas is fine as long as the engine doesn't knock

Would you notice if it knocked and then pulled timing/richened the mixture to stop the knock?

I use 93 in the M3 always, but if I'm driving a Honda that has a minimum requirement of 87, I'l put in 87.

[das borgen]

Would you notice if it knocked and then pulled timing/richened the mixture to stop the knock?

I use 93 in the M3 always, but if I'm driving a Honda that has a minimum requirement of 87, I'l put in 87.
a dyno would notice......... and yes I can notice knock myself

[scooper]

higher compression engines need higher octane gas to prevent knocking. Go with whatever the manufacturer recommends. I believe all bmw 6 and 8 cylinders need at least 91. Not sure about the 4 cylinders. My guess is that they also require premium.

[das borgen]

10.5:1 is borderline though.........i've had a couple of cars with 10.5:1 CR before and they didn t require premium...but of course CR is not the end-all-be-all of resistance to knock

[snowtrax]

Absolutely. It's unnecessary to run it in a car that doesn't require or recommend it though.

[ThreeD]

a dyno would notice......... and yes I can notice knock myself

Of course, if it continues knocking. But if the ECU senses the knock and pulls the timing/richens the mixture to eliminate the knock/detonation, then you wouldn't detect the knock, but the engine isn't "running properly" so to speak (less efficient & powerful)

[GG Allin]

I rarely use premium. Mid grade most fill ups. Car runs fine with it.

[shaeff]

Of course, if it continues knocking. But if the ECU senses the knock and pulls the timing/richens the mixture to eliminate the knock/detonation, then you wouldn't detect the knock, but the engine isn't "running properly" so to speak (less efficient & powerful)

I don't think the ECU actively adds fuel to prevent detonation, but rather the excess fuel is due to the retarded timing. I'd have to look it up, though, as I'm not very familiar with the e36 DME.

[E36BMW3series]

I rarely use premium. Mid grade most fill ups. Car runs fine with it.

I try to never use Mid Grade. My theory is people typically use Regular or Premium, and that the Mid Grade in the tank is older gas. Now, I have no idea how this actually works, so it's pure speculation, but it makes sense to me.



As for me, my car asks for premium 91+, Premium here is usually rated at 91-93. I try to just fill up at stations with 93. Doesn't cost any more, so I try and get the higher level.

The manual on the motorcycle says 87. I started with Premium before I read this, then started just putting regular in it. I think I'm probably going to put a tank of Premium in it every few months. It's 3 gallons, and it can't be bad for it, even if I don't see any benefits.

[adamnur]

Yup. And that's with Premium here is at about 1.53/L too. :(But I've mainly driven BMWs or Jaguars. When I was driving a Ford Expedition, 87 was the best it got...but that thing was huge.

[Moron95M3]

lol at responses w/o reasoning (aka they don't know why they do what they do...)


Das Borgen, thanks for your post :thumbsup:

[BeerSultan]

pretty sure I remember reading BMW "detunes" the engine to accomodate lower-rated fuel. it'll run on 87 "fine"...you could probably run it on 85. all you're doing is causing the engine to run further out of its designed specifications.

i'm no engineer, so i'll let BMW's engineers tell me what gas goes in the car. 93 is what i put in, 91 on rare occasions when i can't get 93.
-R

[esp42089]

I get 30mpg highway on Shell Premium. I get 26mpg in the same conditions with cheap low grade best western gas. I've tried it several times; over a tank of gas, the shell pays for itself. Comes out to 7.5 miles to every dollar verse 7 if the gas is $4 and $3.70 respectively.

[ThreeD]

lol at responses w/o reasoning (aka they don't know why they do what they do...)


Das Borgen, thanks for your post :thumbsup:

:rolleyes: low octane gas can cause detonation for the maps that the e36 is designed to run. maybe 87 will cause detonation, maybe it won't, but there's no way to know for sure unless you get real-time data. since bmw recommends 91+, you should go with that.

[das borgen]

:rolleyes: low octane gas can cause detonation for the maps that the e36 is designed to run. maybe 87 will cause detonation, maybe it won't, but there's no way to know for sure unless you get real-time data. since bmw recommends 91+, you should go with that.

when I dynoed my car (221whp with a catback and M50 manifold) , I decided to do it on 87.................I saw nothing on the plot to suggest knock was occuring and the dyno man (with over 10 years of tuning high power GM and Ford engines with the occasional 7M, 1JZ, 2JZ, 4G63, KA24, SR20DET, etc mxed in) agreed.....maybe I lost a bit of power but there's no way to know until I re-baseline my car with 87 (power pullies were added since then) and re-run with higher octane fuel

how do you figure detonation happens on the E36? is my car a special case?

[ThreeD]

when I dynoed my car (221whp with a catback and M50 manifold) , I decided to do it on 87.................I saw nothing on the plot to suggest knock was occuring and the dyno man (with over 10 years of tuning high power GM and Ford engines with the occasional 7M, 1JZ, 2JZ, 4G63, KA24, SR20DET, etc mxed in) agreed.....maybe I lost a bit of power but there's no way to know until I re-baseline my car with 87 (power pullies were added since then) and re-run with higher octane fuel

how do you figure detonation happens on the E36? is my car a special case?

I didn't remember reading about you dyno-ing your car on 87, and unless you run 87 vs 93 under similar conditions it'll be hard to tell. How do I figure detonation happens? I figure BMW recommends 91+ because it's running a more aggressive map, that will run a different map for lower octane fuel. If you're asking if I have any evidence, then, no, I don't.

[breakfast]

the car can run on 87...but premium is suggested for a reason.

If my car requires it I run it. Some shit bag cars ive had over the yrs didnt need it so they got regular.

prices up here are well north of $5.00 a gallon for premium and have been for a while. Costs me over $80 to fill my tank

[das borgen]

I didn't remember reading about you dyno-ing your car on 87, and unless you run 87 vs 93 under similar conditions it'll be hard to tell. How do I figure detonation happens? I figure BMW recommends 91+ because it's running a more aggressive map, that will run a different map for lower octane fuel. If you're asking if I have any evidence, then, no, I don't.

isn t that what SAE correction is for? to normalize air pressure and temp and humidity and elevation and whatever else?


I don t believe the map is too aggressive too...it is after all, a massively produced street car that lasts well over 200k miles with even just half-decent care.....the S52 is just a bored/stroked/cammed M52B28.........and its CR is only 10.5:1 and it only revs to 6800rpm.....there's not much special about the motor. 75bhp/L is good (or even 80bhp/L for that matter in the event the engine is under-rated) but it s nowhere near being even just borderline good-great for a performance motor.


I can understand why it's good to follow directions but it s only thing to listen and it s another thing to challenge conventions and question norms

[ThreeD]

isn t that what SAE correction is for? to normalize air pressure and temp and humidity and elevation and whatever else?


I don t believe the map is too aggressive too...it is after all, a massively produced street car that lasts well over 200k miles with even just half-decent care.....the S52 is just a bored/stroked/cammed M52B28.........and its CR is only 10.5:1 and it only revs to 6800rpm.....there's not much special about the motor. 75bhp/L is good (or even 80bhp/L for that matter in the event the engine is under-rated) but it s nowhere near being even just borderline good-great for a performance motor.


I can understand why it's good to follow directions but it s only thing to listen and it s another thing to challenge conventions and question norms

Yes, that is what SAE correction is for. I definitely agree that it is smart to question norms, but IMO, if you want to do it, you should do it with some quantitative evidence (e.g. evidence of timing remaining the same, or looking at average MPG between say 2-3 tanks of 87 vs 2-3 tanks of 93, or comparing dyno results of 87 octane vs 93 octane). If you don't want to do those tests, then there's really no reason not to stick to the norm, it's not like premium is that much more expensive than regular anyways.

[das borgen]

i m not saying the cost is the issue...the issue is some people spouting out unfounded and uninformed banter about this being better than that just because the number is higher without looking deeper into things or the "norm" or whatnot

I have that data for fuel consumption by the way and in my car at least, it s been rather negligible the differences I see between 87, 89, 91, 93 when I try real hard to be consistent from tank to tank.

[Volf]

It says right on the gas cap to use premium gas. So of course.

[DLite]

I run regular 87 all day every day as a stop/go commuter, 60 miles round trip. I don't race it, track it, or otherwise drive aggressively very often. I get between 23 to 25 mpg, in stop/go commuting, and about 28-29 whenever I do long highway trips (which isn't very often) with about 192k on the od.

Detonation results in high peak firing pressure and temperature which manifests itself in desposits on the ceramic insulator spark plugs, which I have detected no evidence of.

Now if were to go to the track or autox event, or consistently drive it like a hot rod with long wot, high rev pulls, I would run premium, as I do in the m5, which i do drive like a hot rod.

BTW--Ford trucks recommend BP gas, as per the stick inside the gas door--who's going to argue with that?

[xcore]

shell/chevron/mobile 91 gas only~period. u r arent saving any big number if u do the math, life a dollar or so every tank? and think that you are really smarter than the bmw engineers who developed the car.

[breakfast]

though compression isnt the end all be all.. anything 10 and up should run premium if you want the most out of it(power wise) I dont see it effecting mpg much at all. (if you run lower octane)

[Dricebrug]

Shell or BP. Car has never seen less than 93 (Or at least since I've owned it). Its not that much of a price difference to justify putting in lower octane gas. I also drive my car rather aggressively... always. Put good in, get good out.

[das borgen]

shell/chevron/mobile 91 gas only~period. u r arent saving any big number if u do the math, life a dollar or so every tank? and think that you are really smarter than the bmw engineers who developed the car.
yes, I am

[southpaw]

Shell 91 only here.

[xcore]

yes, I am
go right ahead, it is ur car;);)