[ak335]

just got back from the stealership, becasue my cars engine light was on, and my engine was shaky and it had a very bad idle when i turned it on, dealer said every things fine and i shouldn't be using 93 on my 335i but 89? he says its got something to do with ethonal being high?

[iheartsole]

i use 91 premium! i would not listen to him and put 89.

[GearRex]

Was this Amoco / BP gas by any chance?

I read another thread in this forum regarding BMW denying fuel pump failure warranty claims because of the high ethanol content (above 15%) found in the gasoline used in the car. The owner claims they did not do anything wrong but put gas in the car - how were they supposed to know the ethanol percentage in the gas or which gasoline brands to avoid?.

By this time the owner is caught in a war between BMW and the Amoco/BP gas station owners, both parties refusing to pay for the repairs.

I use 93 octane gas from BP and had not had any trouble so far, but I am getting weary of the postings going around regarding ethanol content in the gas.

By the way, BP = British Petroleum

[ak335]

nope, i use Shell ,exxon

[kevinbahnz]

M-therfucker is lying, ever since I've been driving bimmers all I've used is 93 and no problems. The past 2 years I was going through some hard times.

[tooshay]

you can put 89 cuz it's the minium required octane...91 is prefer. you can put higher just not lower octane.
my m3 prefers 93 octane but the minium is 91 and 91 is the highest octane available in Cali

[tturedraider]

Originally Posted by ak335

just got back from the stealership, becasue my cars engine light was on, and my engine was shaky and it had a very bad idle when i turned it on, dealer said every things fine and i shouldn't be using 93 on my 335i but 89? he says its got something to do with ethonal being high?

Your dealer has been smoking crack.

[bsamoul]

Doesn't the gas door say 91?

[simp0man]

91 all the time

[742]

There are a lot of potential customers out there who will walk away from a dealership if they are told that a car requires premium gas (and the same for synthetic oil). It appears to me that dealerships in general, and the sales people in particular, will grasp at any justification/rationalization to say that premium in not required.

In 2003 I bought a 1.8T Passat, and was told by the salesman that regular gas and regular oil were fine for the car in spite of what the manual said. I ignored him and have run the car on 91 octane gas and the proper synthetic oil since that first day. And lo and behold, he was wrong and the German engineers were right. VW has a massive problem with these engines because of exactly what he told me was OK, while those run IAW the mother country’s guidelines make 200k without a problem.

So the moral of the story is to take the word of the German engineers over the word of the guy on the sales floor. Every time.

[John 070]

Originally Posted by 742

There are a lot of potential customers out there who will walk away from a dealership if they are told that a car requires premium gas (and the same for synthetic oil). It appears to me that dealerships in general, and the sales people in particular, will grasp at any justification/rationalization to say that premium in not required.

In 2003 I bought a 1.8T Passat, and was told by the salesman that regular gas and regular oil were fine for the car in spite of what the manual said. I ignored him and have run the car on 91 octane gas and the proper synthetic oil since that first day. And lo and behold, he was wrong and the German engineers were right. VW has a massive problem with these engines because of exactly what he told me was OK, while those run IAW the mother country’s guidelines make 200k without a problem.

So the moral of the story is to take the word of the German engineers over the word of the guy on the sales floor. Every time.

This stuff only started happening imho when we first got a taste of $3 gas. I had a friend who got a Toyota Avalon. He could NOT get the salesperson to tell him what fuel the car needed. I told him to ask for an owner's manual and the answer would be there. The salesperson didn't want to provide it, so my friend said no manual, no purchase. Anyway, in the manual 87 is the minimum, but premium recommended.

Ditto with 335, 89 is the minimum, so don't try to run 87 in it. Since premium is so cheap nowadays, use it, and don't quibble over 91 v. 93 (out East only Sunoco seems to have both 91 and 93). When fuel shot up 17 cents a week ago, premium only went up 8. That makes premium a relative bargain.

[Blk07335i]

Ask him to explain why...Should be a good one.

[Balthazar_B]

Well, there may be a kernel of truth here. Ethanol as an additive can be used to raise octane, and with the situation in the US around lack of (or unreliability of) refining capacity, and upward trending in crude oil prices, some oil companies may be goosing their octane in premium by adding ethanol above the levels BMW will warranty. And since (I think) the car records the ethanol level in the gas it's burning, you may be at risk of running your car out of spec (and thus out of warranty if you develop engine problems) unless you're careful about what you're feeding your car. IOW, caveat emptor!

Note: I'm not speaking from first-hand knowledge, but the situation I'm describing is hardly unlikely these days.

[crazyeyeskilla]

Stealer is an idiot. Octane has nothing to do with ethanol. Octane is added to delay the combustion of the other components of gasoline. The more octane, the slower the combustion. Slower combustion allows higher compression or turbo/super-charged engines to burn the fuel more efficiently with the added air pressure. You won't hurt the engine using low-octane fuel, but it might run poorly. Ethanol is added to reduce air pollution (supposedly) and is in all gasoline at the same concentration, barring E85 (at least here in CO).

[Balthazar_B]

Originally Posted by crazyeyeskilla

Stealer is an idiot. Octane has nothing to do with ethanol.

Au contraire, mon ami! At least with your second sentence; this dealer may in fact be an idiot, but not on the issue of ethanol.

http://www.ec.gc.ca/cleanair-airpur/...as/ethgas4.htm

Look at section 4.2. Now while there are RON and MON nuances that affect the quality of the octane boost, there is no doubt that adding ethanol boosts octane (and sadly seems to be becoming the preferred method of doing so).

[alan93rsa]

I use Shell 93 in Ohio. I have not checked the % ethanol on the pumps here but I noticed a pump in Toronto this week that that showed all 3 Shell grades and the % ethanol. It was interesting to see that the low grade was 10% ?, the mid 5% and premium 0%. I'll have to check a pump in Cincinnati the next time I fill up.

[Year's_End]

Wonder why they only offer 91 in Cali. We don't have 91 on the east coast, just 93.

[Balthazar_B]

Originally Posted by Bimmer Loyalist

Wonder why they only offer 91 in Cali. We don't have 91 on the east coast, just 93.

Possibly because large parts of the state are mountainous, and that many flatlanders frequently drive into the mountains. So perhaps the same reason only 91 is available in places like Colorado?

[Lassaxi]

Originally Posted by crazyeyeskilla

Stealer is an idiot. Octane has nothing to do with ethanol. Octane is added to delay the combustion of the other components of gasoline. The more octane, the slower the combustion. Slower combustion allows higher compression or turbo/super-charged engines to burn the fuel more efficiently with the added air pressure. You won't hurt the engine using low-octane fuel, but it might run poorly. Ethanol is added to reduce air pollution (supposedly) and is in all gasoline at the same concentration, barring E85 (at least here in CO).

If you're going to call someone an idiot, you should at least know what you're talking about. Ethanol is added to gas BOTH to boost octane and reduce carbon monoxide pollution. The octane "number" (i.e., 87, 89, 91) is a rating that measures resistance to detonation. Gas with higher octane ratings do not necessarily have a higher fraction of actual octane. Ethanol increases gas's resistance to detonation, thus adding ethanol increases the octane rating.

[Lassaxi]

Originally Posted by Balthazar_B

Look at section 4.2. Now while there are RON and MON nuances that affect the quality of the octane boost, there is no doubt that adding ethanol boosts octane (and sadly seems to be becoming the preferred method of doing so).

Sadly? Given that the alternatives to ethanol as an octane booster are basically MTBE and TEL, I'd say ethanol is probably the least bad choice.

[hunt55]

Originally Posted by ak335

just got back from the stealership, becasue my cars engine light was on, and my engine was shaky and it had a very bad idle when i turned it on, dealer said every things fine and i shouldn't be using 93 on my 335i but 89? he says its got something to do with ethonal being high?

I had a Sears technician tell me that over the phone when I called about my garden tractor sputtering with a bad idle. Turned out to be a clogged pin hole in the gas cap. Sound like your dealer also advises Sears.

[in5ane_3]

Your manual is written by the people who made this car, who worked on it for years. Listen to what they have to say not a SA at a dealer. Fill up with 91 or 93 and you'll be fine.