View Full Version : what kind of gas do you put in your E30?

Chris de la Cruz
07-21-2004, 10:43 PM
Yeah gas has been drilliing a hole in my pocket... spend most of my income on gas:mad: i put 89 octane on it.. my dad tells me never to put regular. so i still obey him... he says it used to always been 92 octane all the time but since prices went up its been 89... what kind of gas do you put? is there any difference if i put regular gas?

07-21-2004, 10:45 PM
It's not very good for your car especially if you have a performance chip..

07-21-2004, 10:52 PM
87 is best.
Don't use anything higher unless you NEED to use it.

Chris de la Cruz
07-21-2004, 11:01 PM
^^^ really? but meh.. i think i'll stick to the 89 or 92... thats the only gas put in since we had the brand new.

07-21-2004, 11:07 PM
if i go to sunoco, i put 94 :(

07-21-2004, 11:21 PM
92 oct.

anything less and my engine pings bad.

07-22-2004, 12:41 AM
my bro puts in 94 octane in his e30...


07-22-2004, 06:06 AM
if our Engine His stock, no Chip no High compression piston etc etc you dont need high octane gaz.. the octane it juste de resistance of gaz on high compression.
At 8.8 :1 a standard M20 isn't a high compression engine...
A performance Chip change ingnition timing so higher octane Ratio will help..
only a cam i dont thing you need higher octane gaz... you wasting your money! in fact sometime car made for 87octane Suck more gaz on higher octace rating Gaz. because it take more energie to burn the gaz.
i always put 87! my engine stock. ( except for a drop in K&n but its not really a mod.) it doesn't clean your engine.. it doesn't not give you more power. octacne just increase the resistance of gaz to compression so it will not explode before the ingnition.

07-22-2004, 10:05 AM
Put 87 in a non-chipped internally stock M20. Anything more and you're actually hurting performance (I ran acceleration times).

Chris de la Cruz
07-22-2004, 10:39 AM
^^^ aright thanks man... never knew that. we've always been puting 89 plus in this car since we had it brand new... alll that wasted money :D

07-22-2004, 12:12 PM
I use 94 octane


07-22-2004, 12:27 PM
It's weird, mine only requires 87 octane but I have found it really does run better with premium.

07-22-2004, 12:52 PM
i only put 91 octane in my '86 325e. and just the other week i drove it up to Algonquin park and got 600km/tank. gotta love the E.

07-22-2004, 02:46 PM
octane does nothing, go to how it works web site. you will never need high octane unless the motor has been chipped or is high compression. put it this way, my land cruiser has a hopped up motor to say the least, it has 11.5/1 compression. that is, it needs high octane fuel, 92 plus an octane booster, i wont pay for race fuel at 5.50 dollars US. but the bimmer does not because it is not high compression. the detergency might be different, but that will only hurt your rubber in the lines(ie the fuel pump, injector o-rings, or even the rings on the motor by removing oil that it needs for lubrication). the gas up in canada will be different from the gas here in texas for sure, different climate. but the fact that you car does not need high octane gas will not.

go here and read about it, and stop wasting money.


07-22-2004, 04:01 PM
That article doesn't explain what 115 would be, but I assume the high octane content plus the lead or lead substitute elevates the compression-ability (is that a word?) to what 115% pure octane would be.. interesting. So, if you take 94 octane (highly refined gas) and add 105 octane boost, it really just make it more compressable.

Imagine what 100% pure heptane would be like? Good for ping pong ball bombs. :)

07-22-2004, 04:23 PM
to those who put higher octane than regular(if it is stock) don't you experience any pinging?

07-22-2004, 06:54 PM
no you use highr octane so it wont ping, that is detonation, when the mixture explodes to early, before the spark. octane doesnt mean better performance, we build trucks that run on propane and that has an octane rating of 105-115, but it accually looses power, less btu's of energy then petrol. for those of you saying that "mycar runs better", are wrong unless it has been tuned and you have to. stock engines will run fine with lower octane.

07-22-2004, 07:43 PM

Chris de la Cruz
07-23-2004, 12:18 AM
sorry but whats pinging?

Krim 325I
07-23-2004, 01:27 AM
im putting race gaz called 100LL (low lead). If i dont it ping like whoa.

07-23-2004, 11:58 AM
^^^is your car stock, because then you dont have to. pinging is detonation, or when the gas combusts before the spark hits it. go back and read the article from how stuff works. you guys if your car is stock and you think it is pinging if you dont use supreme, get you car looked at. there is no way that they need it. that is like saying, my car is old and i need the high octane to run good. that only applies to muscle cars, some of them came factory with compression ratios as high as 14.5/1. your car even with 9.0/1 will still accept low octane fuel. why do hondas run low octane fine when they have more compression then you bimmer, because 9(+/- .5)/1 is not high compression. only if you car is modified or maybe the car has so much carbon it is raising your compression will it need the super. end of story, sorry for you guys that think you need to waste money. if you dont know what pinging sounds like you should take it somewhere, fuel injectors, exhaust valves, ehaust leaks will really mask sounds that only mechanics familiar with them will notice.

Krim 325I
07-23-2004, 02:08 PM
nope my car is far from being stock. im running a 97 3.2 engine along with tms chip and cams.

07-23-2004, 02:13 PM
Pinging or "knocking" happens when you run to low of an octane in a car. Most cars nowadays have anti-knock which basically retards the timing when to low of octane is detected.


07-23-2004, 06:49 PM
m20's dont have that and still dont need it. new cars have them but it retards the timing because of the detonation not because too low an octane is detected. that doesnt mean shit since you still have a stock m20 and pay to much to drive it?!?!?!? pinging can happen for a few reasons, not just too low octane. you could have carbon on the pistons that will stay hot (ie hot spot) and that could detonate the mixture, you might need a tune up, carbon on the valves, worn timing belt/chain, etc., etc. anyway those things can be more problematic then they help, like how does it know the difference in noise, they dont they can even retard the timing so much as to overheat the car. i have seen this and other problems happen with knock sensors, anyway this is not the topic. STOCK CARS CAN RUN ON REGULAR GAS, WITH NO (I REPEAT, NO) PROBLEMS!!!!!

07-23-2004, 08:43 PM
stock engine = use the gaz that BMW says in the manuel, if you modify it, chip, turbo etc etc. use higher octane.. that'S a fact not opinion!

if with stock engine you got trouble eith 87 octane... it's because youre engine got problem.