anyone ever run 87 in a 540i?

[markus]

just cruious. i went into one of those full serve stations unkownlingly and I think the guy put 87 in after I specifically requested 89. would this harm my engine? Also on cooler mornings the car will idle kinda rough. Time for intake gaskets?

[Evan]

it won't harm the engine... but you will be able to tell the difference in performance since you're a Premium gas user.

as for intake gaskets, check for vacuum leaks... download the TIS and use that, also.

[Ross]

According to things I've read typically premium fuels are lower in sulphur than the lower grades. This is very important if running a nikasil motor.

[swenpro]

just cruious. i went into one of those full serve stations unkownlingly and I think the guy put 87 in after I specifically requested 89. would this harm my engine? Also on cooler mornings the car will idle kinda rough. Time for intake gaskets?

Do you have a chip that requires a minimum octane? If not, no worries, I've run a couple of tanks of regular gasoline w/ no problems

[Tiger]

Sulfur is not an issue anymore. Not when compared to gas in 1995.

[Tiger]

What fuel mileage did you get when you use 89 octane? I once did a test... I get 320 miles per tank city driving on 93 octane and I only got like 240 miles on 89 octane.

[markus]

hmm
according to my OBC im now averaging 21.4 mpg. I did the mathematical approach and found out im really getting around 22-24mpg overall. Not bad.

Im just curious to see if my car really NEEDS 89. If 87 is ok then ill save a few bucks.

[markus]

nope. no chips here.

[Evan]

I only use 93 or 94 Top Tier gasoline... it costs me an extra $150/year

[shurton]

hmm
according to my OBC im now averaging 21.4 mpg. I did the mathematical approach and found out im really getting around 22-24mpg overall. Not bad.

Im just curious to see if my car really NEEDS 89. If 87 is ok then ill save a few bucks.

You'll get better milage with higher octane gas, so the price difference is minimal.
I only use Chevron 94, or Shell VPower

[Tiger]

Marcus... what type of driving do you do? On a long trip of all highway, I get 24.8 MPG. I always calculate what I fill against what my trip meter say I traveleled... computer can be way off if there is not a substantial miles in the calculation.

[BuckNaked]

Why not pick up a can of octane boost?
You should stick with 89 octane or better.
Your engine is computer regulated for fuel mixture and the low octane may give you problems if you run out the whole tank.
BMW goes out of their way to inform you of the octane requirements.
At least top off with 93 as soon as is practical.