Gas mileage sucks

[GaryS]

I'm new to BMW bikes but I get about 33mpg on my 04 r1150. It came with a Leo Vince SBK slip on and a Dobeck TFI electronic jet module. The Dobeck disables the O2 sensor to work as an "open loop". Who knows if I'm getting greater performance but could it cause such an mpg drop?

[sweatmark]

I'm new to BMW bikes but I get about 33mpg on my 04 r1150. It came with a Leo Vince SBK slip on and a Dobeck TFI electronic jet module. The Dobeck disables the O2 sensor to work as an "open loop". Who knows if I'm getting greater performance but could it cause such an mpg drop?

The Dobeck/Techlusion typically richens mixture, reducing fuel economy, as you likely already know.

Remove the Dobeck or "zero" it to reapply OE fuel control, measure fuel economy, choose your next move.

R1150** fuel injection discussion that you might find useful:
http://www.advrider.com/forums/showthread.php?t=749080

A quick googling will turn up similar resources.

[f4tweet]

Are you getting 33mpg combined road/city driving or just city? Your figures are spot on for just city driving. I am looking for a gas station every 130 miles with all city driving.

I just filled up @100.3 miles and got 35mpg combined driving.

BTW: I am running at 2.91 (31/11) FD.

[towerworker]

I know that if I "get into it" my mileage drops severely, but when I run "normally" I average 50. (highway) That's running 60-65. I have ridden two-up on the Blue Ridge Parkway (45-50) and gotten 54.6 mpg. I will add that my passenger was not a light-weight.

Bike is completely stock.

[jrsndman]

I typically get between 35-40mpg. About 50/50, city/highway miles. I have a full Two Brothers exhaust and am told there is a Rhinewest chip in the ECU but, haven't ever checked. I'm almost never "light" with my right hand.

[towerworker]

I've always found it interesting to look at mpg numbers when comparing different vehicles. I could get 44 on a 2002 Civic w/ac running on interstate. Average 50 on the same road w/R. With my S10 about 26.

I've had people tell me they wanted to get a bike so they could commute back and forth to work to save money. You don't ride a bike to save money. You ride it to have fun and to enjoy the experience. If anything the cost per mile on a bike (like ours) could be higher than a reasonably priced economy car. It's all about the experience.

[GaryS]

If I take out the Dobeck TFI but leave the Leo Vince muffler on, does that change the leanness or richness I've read about? I believe the O2 sensor was removed with the Dobeck installation. I'm wondering how big a deal is it to restore all that to stock.

[peels]

I've always found it interesting to look at mpg numbers when comparing different vehicles. I could get 44 on a 2002 Civic w/ac running on interstate. Average 50 on the same road w/R. With my S10 about 26.

I've had people tell me they wanted to get a bike so they could commute back and forth to work to save money. You don't ride a bike to save money. You ride it to have fun and to enjoy the experience. If anything the cost per mile on a bike (like ours) could be higher than a reasonably priced economy car. It's all about the experience.

indeed. I bought my bike because Ive wanted one for years....BUT...the fuel savings are a HUGE bonus. It just barely pays for itself, so... my fun riding...it's guilt free. I can tell my wife I'm riding to save money lol!

for comparison: mine gets mid 30's if I'm city driving or romping on it. 40-45 regular commuting. which is 5 blocks/3 stop signs in town, and 6 miles highway. one tank was close to 50, when all highway. While My truck gets 15. So its a "have my cake and it too" sorta deal-and I love it.

OP: try running with dobeck off. see what happens. unless you have other mod besides pipe, it wont hurt I don't think. Unless you take it off and runs horrible or really hot...Ive never used one on a BMW personally, but the idea is the same...richen up at different rpms to get power, or smooth it out.

[CycleRob]

GaryS,

My wife's new Sentra with the computer controlled steel belt CV transmission routinely gets 38--39 MPG with HER driving it. I got 42.6 on a "speed limit only" trip. It is always put into "Eco" mode. My F800ST varies from 58 to 74.4 MPG, usually 64 in winter 67 in summer with conservative riding. My long gone OilHead usually got 48 MPG in everyday riding. With motorcycles, a lot depends on the body weight and throttle hand of the rider, tire pressures, drag from windscreens, luggage and the state of engine tuning, so there is a lot of wiggle room even with the same year/model bike.

The O2 sensor trims the fuel mixture as it modifies the default firmware fuel map to obtain the optimum fuel ratio for the current RPM and throttle settings. The barometric sensor within the Motronic box also changes the current mixture as the altitude and/or barometric pressure changes. Without the O2 sensor, you are running on the default open loop fuel map, which the aftermarket mfgr's often enrichen from there with "electronics" for better "performance". Yes, there is a fatter, more immediate throttle response that can be addictive as you pump the throttle and stir the gearbox, but not much of that is as important as fuel mileage when you're out for a 4 hour ride on the interstate or riding with the normal traffic thru the countryside. Your spark plugs most likely are always black with carbon deposits and do not last as long as they should.

At current gasoline prices, especially for mid and premium grades, that so called better(?) performance comes at an increasingly annoying high price. You are also creating additional combustion chamber carbon deposits in a large, heavy engine on a bike that was apparently designed for economical, vibration free, effortless cruising at 80 MPH while spinning the engine at only 4,000 RPM. Straying from that original intention, especially for high performance, on an OilHead will come at an unjustified higher price.

Bottom line, you need to reinstall that O2 sensor if you value better fuel economy and a cleaner running engine over what you have now. You don't say if you still have the stock exhaust's CatBox installed, but there should still be a threaded O2 bung on every performance exhaust header. Hopefully, and this is the case almost 100% of the time, the O2 sensor is still there and only unplugged from the wire harness.

[BoxerSteve]

indeed. I bought my bike because Ive wanted one for years....BUT...the fuel savings are a HUGE bonus. It just barely pays for itself, so... my fun riding...it's guilt free. I can tell my wife I'm riding to save money lol!

Just don't tell the wife that the increased maintenance and tire expense more than offset any gas mileage savings. No $ are saved by riding a MC instead of driving a cage. Sure is more fun though. Most of the time...

[vitaminC]

My bike is basically stock and I average a consistent 39mpg while commuting (about 50/50 hwy/local), with my light coming on around 150.

[BruceinLA]

I got 38 mpg when my cat code plug was disconnected, now I get 42 mpg with the Yellow cat code plug in place.

I ride it like I stole it most of the time, my average commute is 6 miles fast (40-45mph) roads, 7 miles at 75 mph on fwy.

tires cost more, fuel costs less, insurance is only 10% of what my accord was.

[towerworker]

I guess much of a potentially higher operating cost comes from tires. A pair of good motorcycle tires is close to the price of 4 car tires. And then they last 1/5th as long.

I learned how to install my own tires as well as balancing them. The local bike shops will only install what they sell so I buy them online and do it myself.

[peels]

indeed. I bought my bike because Ive wanted one for years....BUT...the fuel savings are a HUGE bonus. It just barely pays for itself, so... my fun riding...it's guilt free. I can tell my wife I'm riding to save money lol!

Just don't tell the wife that the increased maintenance and tire expense more than offset any gas mileage savings. No $ are saved by riding a MC instead of driving a cage. Sure is more fun though. Most of the time...

shhhh.

youre gonna ruin it for me.

[towerworker]

Even if my bike got 20 mpg I'd still ride the heck out of it. Great therapy for an old fart!

[gregor]

With three piece hard luggage and a BMW fly screen I've always got around 160 miles to warning light. 16 litres thwn roughly to top up.
Which I make as 45 mpg UK or 38 mpg US.

So, the solution is to fill up with UK gallons to improve those mpg.