Eating Gas !! 04 K1200GT - with sidecar

I just rode my 04 K1200GT with a Hannigan Classic side car from Detroit to Tucson, Az. I was only getting 25 mpg. This seems like a lot more than normal. Does anyone know of problems that would adversely affect the mileage? Iron Horse M.C. of Tucson said that a faulty oxygen sensor could be the culprit. Has anyone had this problem? Any advice would be appreciated.

Please review: http://forums.bmwmoa.org/showthread.php?46057 - I'll add that info to your thread title.

In response to your question -

What is the normal MPG you get with this rig? Sidecars aren't known for fuel efficiency..

Things like wind, temperature, speed can all greatly change fuel mileage. Running uphill in cold weather into the wind at 80MPH, that mileage wouldn't surprise me a bit.

As far as the O2 sensor - if it was really defective the ECU would default to an internal fuel map. While these tend to be a bit rich - they aren't that rich. A check with a GS-911 will tell you if the sensor is good or bad.. and give you some idea of how the engine is running.

Like Don said, I would get it plugged in to a diagnostic tool. No point in just guessing and replacing parts without a complete check. That's definitely poor mileage. It's possible that winter fuel additives may have attributed a bit, but I wouldn't expect to see that much drop. I got 30-33 with my rig pulling a trailer at 70-75mph.

Getting over 30 miles form a sidecar rig WITH a trailer is borderline bragging. It is outstanding mileage. Getting 25 mpg from a K1200GT is within the normal range. Remember it is wind resistance AND you have more wheels to roll.
The rolling resistance of the tires on a Hannigan rig is not even close to a motorcycle tire. Just figure your contact patch.

Wow Bob, that is phenomenal mileage! On our cross country trip to Oregon last summer the best I got was high 20s. The worst was crossing the high desert against a headwind at 90mph where I got only 18mpg. The only time I ever broke 30mpg was on backroads at 45-50mph. Adding the ragtop was great for Barley, but I most definitely felt it in my fuel economy.

Normal on our rig with two people and camping gear is around 32-33 mpg at 75mph. Headwinds, especially quartering headwinds, can cut that as low as 20mpg or less. On the way to the 49er one year we ran into a vicious quartering headwind in Nevada. We gassed in Carlin and burned an entire tank of fuel getting to Eureka, which is about 95 miles--pulled in on fumes. Next day, we were again making 32-33 across Hwy 50. So yes, headwinds and winter fuel could easily drop you to 20mpg or less. But if you're consistently in that range, it's time to take the advice you've already been given and use a GS911 or a dealer to read the codes and see if you have a problem.

Best,