hey all,

here's my situation, i was originally looking to get a 528i as a daily driver and had not considered a 535i bc of the fuel pump issues, need for premium gas, and slightly lower gas mileage. now before you guys jump on me about using premium vs regular gas, i drive ~35k to 40k a year and with price difference of about 30 cents a gallon and still headed north, it'll save me a few bucks over the years.

so i came across a post on 5series.net that mentioned a 535 with a jb4 was hitting mid 30's mpg. now i'm reconsidering bc although i have a second toy for the weekend i wouldn't mind having a daily with more power on tap with a higher mpg than the 528. for those of you with jb4, what are your experiences with mpg? anyone run the turbo off setting for a lengthy period of time?

My 535 with the jb4 gets 24 around town and 28 on the hwy

I'm not 100% certain - but I think BMW recommends 91 octane gas for ALL their cars.

Also, I'm not trying to sound like a jerk but if you are worried about gasoline costs based on 30k - 40k annual miles then the anticipated maintenance costs will probably be too much for you. Your annual mileage would suggest at least one set of tires, brake pads and most likely rotors, and 2-3 oil changes per year. And we haven't touched on repairs/aftermarket warranties.

Maybe you should look at something less expensive for this kind of use or at least consider a Diesel or Hybrid.

I drive a lot as well. Not as much as that guy, but I understand his concerns. There's fuel mileage and equipment/maintenance costs but there's also comfort and driving something you enjoy. I didn't buy my 535xi because it was good on gas, but because it gets decent fuel mileage and it's comfortable, quiet, powerful, and just a touch sporty. But if it got 16-17 mpg, I wouldn't buy one.


I also want to know what people are getting, mpg wise, with the jb4.

I'm interested to know more about the benefits of the JB4 tune as well.

Power, bad ass power...!!!

I don't want to say you get better mileage with the JB4, but from my personal experience I didn't lose any. I drive 25 miles to work each way rual and interstate. My car during this time reads 24.7-25. When I go out of town and reset the system, and 90% is interstate its says 28-29 and then slowly returns to the 24 range when I return. The power increase is really nice.

here's some info about map 8 from the e9x folks. I can't wait to get my jb4 in and try it out. I already get 28-29 mpg now on the thruway a few more would be nice.

which map do you run? how often do you run map 8?



i understand what you're getting at and i went to test drive a prius and seriously considered it for awhile. but thankfully i came to my senses and realized i don't want to waste the next few years of my life living in one :P i did the whole hypermiling, econobox thing the last several years and i decided it's time to live a little...with some practicality mixed in. i've considered other hybrids and non-hybrids as well and as someone mentioned there are other factors that make the 535 a great choice for an all arounder. the reason i ask specifically about the jb4 535 is bc i would only use premium gas for FI or high compression ratio motor such as the 535 and want to know how it compares to the 528's fuel efficiency which CAN run on regular fuel w/o issues.


link???

28 hwy wtf I get like 21 hwy lol, something must be wrong with my car! :doh: