Posted by John Dilzell on August 18, 1998 at 12:06:24:
In Reply to: Re: Jim C Chip Available for E34 .. MPG -> E39 posted by Loof on August 15, 1998 at 15:14:47:
: I understand you're running premium gas now, but what about before? Specifically I'm wondering about the '98 540i manual which states the requirement or recommendation of premium gas (with the stock chip). In other words, the car may already be tuned to high octane fuel.. and a modified chip for this series BMW wont help as much as for the older generations. ?
: : 3. I used to average 21.5 MPG (based on OBC)and so far with the JC chip I'm getting 23+. My driving is mostly highway.
I'm currently using 93 octane which is what I've always used with the stock chip. The difference is now I have to use high octane whereas before I could get away with low or mid octane since BMW detunes the cars to run on lower octane fuel. At least this is what the chip tuners say.