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!! :p

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.

[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!? :D

[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

[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....

[KenB]

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.

Are you serious??? 35 mpg isn't good enough? The best I've gotten is around 33mpg on a 20 mile stretch of flatland on the way to the shore here in NJ, cruise on 65mph, no stops, air on.


Don't pass the trucks, draft them.

[Scott E]

He had a 64' VW bug and would get so close he could take his foot off the gas pedal and barely use any gas since the bug was at an idle.

[Mr Project]

Only 35mpg? Isn't this kinda like complaining that you only get to have sex 3 times a day? :D

[DueyT]

Only 35mpg? Isn't this kinda like complaining that you only get to have sex 3 times a day? :D
Exactly! *LOL*

[jplacson]

Just wondering... what mileage does your Merc get???

[Tiger]

His Mercedes gets 100 MPG... heh heh

[stevebuk]

I haven't owned a 535 but I used to have a 735i - I was lucky to get 32 mpg (imperial gallons) on a long run. I get an average of 25 mpg on my 520i and a little less on my 525i (imperial gallons).

[ryan roopnarine]

well, when its operating on one cylinder bank, ie, as an inline seven, it gets up to......

sorry, i was being facetious. the model under my name does not exist in the real world. it only exists in the 1999 song "bling bling" by bg, et. al. the closest i got to buying any merc was a w126 from the mid 80s and a w140 S-wine class 560SEL that i didn't buy because i thought the bmw would be easier on maintenence :D. Shoulda got the 89 e32 750 though, the price was right, if i knew that i was gonna have to do soooo much wrenching on my own, well....not much difference other than gas mileage.


Just wondering... what mileage does your Merc get???

[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. :)

[ryan roopnarine]

if i could address everyone suggesting that i drift behind trucks.......the speed limit on this road is 70 mph, so the trucks do about that. if i was to increase to that speed, i am assuming that i will lose whatever advantage i gained in following behind them...Right? is there some dramatic increase to be gained from tailgaiting a semi.

[bahnstormer]

yes your square block shaped car won't have to cut through the wind since the truck is doing it for you.

not very safe though...

i'm still wondering if this is a joke or what?
91 535i highway no stops 22mpg MAX

[KenB]

if i could address everyone suggesting that i drift behind trucks.......the speed limit on this road is 70 mph, so the trucks do about that. if i was to increase to that speed, i am assuming that i will lose whatever advantage i gained in following behind them...Right? is there some dramatic increase to be gained from tailgaiting a semi.

Get close enough behind a big rig and you can just about put it in nuetral when you get close enough to get drawn in behind in the suction that is formed there. Seriously. I've done it (not recently) and it works. It IS a bit nerve racking and you better be sure the truck driver knows you're there. Most of them won't allow you to do it. I did it on the open interstate late at night in the middle of IOWA, nobody else on the road, etc.



Disclaimer: I do NOT condone such driving. ;)