why can't my e34 get more than 35 mpg?

[ryan roopnarine]

is there a dynamic "limit" that anyone is aware of? i tried to achieve my ideal sweet spot driving home today, which is 3 gallons per 106 miles (or the distance from gainesville to orlando). with the a/c engaged 25%, cruise at 58 mph, no headlights, wipers lowest, I could only get to about 34.8 mpg before it plateaued. I stopped once for someone on the side of the road (45 seconds) and took 45 seconds at a toll booth, as well as one 55-95 sprint to get out of the way of a convoy (and to keep my sanity). I carry about 50 lbs of tools in the trunk, as helga hasn't been as reliable as i hoped she would be. is there a formula, like 10 hp for .1 off 1/4 mile time, for the coefficient of friction and fuel mileage? I might be being a little unreasonable expecting 36 from a 4.10 rear end, buuttt....i'd like to at least once make the trip on three gallons exactly.

[rickm]

You still fighting that tire?

[Brian C.]

OK....if you're gonna start bitchin' about ONLY getting 34mpg, then maybe you need to change a diaper or something. Seriously Ryan, I'd say that most anyone here would KILL to get that kind of mileage. If you really want to increase it I'd say that you must keep the optimal conditions constant. No changes at all. And every little variable must be addressed too.

constant speed....no "passing moments"
elevation...Fl Turnpike, no problem
wind resistance....not much you can do about it
weight....strip down....not YOU ...PLEASE!!
tire inflation
yadda-yadda-yadda

If you were to fill up at say Ft. Drum, drive to Okahumpka, fill up again and do the math while keeping all the variables, you MAY squeeze a few more out. But I think you are pretty well at the wall where you are now. Maybe all that WD40 on the rims is holding you back!!

Brian C.

[ryan roopnarine]

never mind, the obc's standard deviation per use is more off with 89 than 93, ie it lowballs it despite not having a knock sensor....the car likes 89 more and gets better mpg on it. calculating it out makes it 35.21212121, not quite the 35. 33333 to be a flat 3 gallons per trip, but too close for me to quantify. some of that crap in the trunk is coming out though, looks like it could make it. the tire struggle begins anew tomorrow morning at 7, as mumsies brakes need to be mic'd and caliper pinz regreased to eliminate that classic ford taurus shudder, and it needs to be done before 10, the optimal time for spontaneous combustion at this altitude. IE, i expect to become sufficiently demented from the heat to pull out the sawzall at about lunchtime.

[Brian C.]

Man....summer was right on time. Not much rain for the past month or so, then summer started Monday, and every afternoon now it's the 2-3pm rumbles!! Nasty lightning at night too.

Brian C.

[rickm]

Man....summer was right on time. Not much rain for the past month or so, then summer started Monday, and every afternoon now it's the 2-3pm rumbles!! Nasty lightning at night too.

Brian C.

Up here in NC we are getting a few...rain every single day. My lawn should be ready for harvest any day now. :P

[Kamil]

Next time, don't pass the convoy of trucks... just drive closely behind them.

Damn... my 535 gets 22-23 on the hilly highways b/w NYC and Boston.

[Kamil]

You may also try investing into the "tornado air management system" better gas mileage and much more power... how can you go wrong!?

[Sweetwater]

Here's my idea.

Empty that fuel tank to 4 gallons. That will still give you a 33% range buffer. And even though gasoline has a lower density that water, if you drop 20 gallons or so, at 8 pints per gallon, that's a net weight reduction of 160 lbs right there.

Better than going on a diet yourself....

[TimGinCentralNJ]

Tim G.
'91 535iM
120k

Next time, don't pass the convoy of trucks... just drive closely behind them.

Damn... my 535 gets 22-23 on the hilly highways b/w NYC and Boston.