Premium gas?

[Rina120]

So I used to have a 94 525i and i used 89 octane gas.
Eventually, the gas tank imploded, I'm not sure if this is related to the gas or not.

Anyhow, I got rid of that car and now I have a 93 525i. The previous owners put premium gas only in it. Since I have had it (July), I have used 89, like I usedin my previous one.
This past weekend, I actually took a peek at that note in my gas tank and it says PREMIUM GAS ONLY.

So what gives? How come 89 was good for my 94 but I need premium for my 93? I thought you only had to use premium if you chipped the car?
What do you guys say?

[infinity5]

You should be fine so long as it's not knocking. Read your manual. theres a whole section on gas requirements (or there is in mine) and for my m60 it said something along the lines of "USE PREMIUM GAS ONLY!!!!! (and then a few lines down) but anyhting with at least 89aki is perfectly fine"
*shurg*

So I used to have a 94 525i and i used 89 octane gas.
Eventually, the gas tank imploded, I'm not sure if this is related to the gas or not.

Anyhow, I got rid of that car and now I have a 93 525i. The previous owners put premium gas only in it. Since I have had it (July), I have used 89, like I usedin my previous one.
This past weekend, I actually took a peek at that note in my gas tank and it says PREMIUM GAS ONLY.

So what gives? How come 89 was good for my 94 but I need premium for my 93? I thought you only had to use premium if you chipped the car?
What do you guys say?

[Springfield1952]

The gas tank imploded?? What's up with that?

Curt.

[chamilun]

is 89 aki the posted number on the pump? ive been running 93, but if 89 would be good, id switch. the octane rating and sulfur content are not related (m60 engine).'

i thought that 'aki' or anti-knock index was different than the number shown on the gas display.

any opinions on this??

[Bill R.]

vanos has knock sensors and the gas they specify is 89 aki and the older m50 specifies 90 aki since it has no knock sensors If yours is a real early 93 it could have been a m50 motor not the m50tu, if its a later motor then it should be the same as your 94 was...

So I used to have a 94 525i and i used 89 octane gas.
Eventually, the gas tank imploded, I'm not sure if this is related to the gas or not.

Anyhow, I got rid of that car and now I have a 93 525i. The previous owners put premium gas only in it. Since I have had it (July), I have used 89, like I usedin my previous one.
This past weekend, I actually took a peek at that note in my gas tank and it says PREMIUM GAS ONLY.

So what gives? How come 89 was good for my 94 but I need premium for my 93? I thought you only had to use premium if you chipped the car?
What do you guys say?

[tdgard]

This summer I read an interesting newspaper article about this subject. They had spoken with several auto manufacturers about octane. The quote I remember most was from a Porsche engineer that basically said sure we put premium stickers all over our cars, but they also have to work all aver the world including those places where premium is not available. All the manufacturers stated that you would not be doing any harm—just maybe a slight decrease in performance. Maybe Mark can chime in and explain why, after chipping, we need to put in premium. Is it a drivability thing, or would you just not be getting the full effect of the chip?

[George Davis]

Chamilun, in the US the number on the gas pump is the aki.

[Derek A.]

One of the benefits of premium fuel is the extra detergents in them. Have seen an intake tract or two that are really messed up due to crap gas.

[Rina120]

Hmmm.interesting. So how can I tell if I have a tu or not?
And I have never heard a knocking noise. Is it obvious? Will I know it when i hear it?

vanos has knock sensors and the gas they specify is 89 aki and the older m50 specifies 90 aki since it has no knock sensors If yours is a real early 93 it could have been a m50 motor not the m50tu, if its a later motor then it should be the same as your 94 was...

[Bill R.]

m50tu if its 9/92 then it could go either way and you have to look at the motor to determine if its vanos or not... vanos will have a bulge on the drivers side of the timing cover up near the top of the head

Hmmm.interesting. So how can I tell if I have a tu or not?
And I have never heard a knocking noise. Is it obvious? Will I know it when i hear it?