Hey all,

I've been poking around the internet trying to establish a baseline fuel efficiency for a 2001 f4i. It looks like most people are getting somewhere in the neighborhood of 40mpg. I just bought mine about a month ago, and through two tanks I've gotten closer to 25-28; usually right around 95 miles when the reserve lights tick on. I filled up with ~3.8 gallons this morning at 105 miles and one Res bar down.

I'm commuting mostly on surface streets, and I'm not beating the hell out of it; most times my RPMs are < 6k. My bike has 29k miles on it, but I just had the 30k mile service done on it, and replaced the CCTL and fuel pressure regulator a bit ago. With the service came new spark plugs, tires, and a serious engine sync. Everything else should be "perfect" per the mechanic (who's a known reliable guy in town.) I haven't put a full tank through since the service, but I don't -think- I've seen an improvement since then. I've been throwing some B-12 Chemtool in with the gas since I bought it to try and clean out any gunk.

I'm pretty sure all the mechanical bits are stock (certainly the exhaust), though the air filter might be aftermarket. I'm filling up with 87 octane, per MoM. It's not a CA model, so it shouldn't have an O2 sensor.

Any thoughts on whether (1) I'm expecting too much for gas mileage or (2) what the problem might be that my bike is so thirsty?

Thanks

 

I had to replace a rear tire from a nail and I did the job myself. When I put wheel back on the Bike I didnt have any axle grease. My mileage dropped significantly, though not to your degree. Since I put the grease I havent seen the reserve bars and Ive went up to 120 miles before I put gas.

This may be wayyy off but it had an impact on my mileage.

 

Wow that's not very good. I get around 40mpg. Usually I fill up when the reserve comes on at around 135 to 140 miles to a tank. I have pushed it to 167 miles on one tank and I barley made it to the gas station. My bike isn't stock. It's got a slip-on power commander and K&N filter. Havent replaced the plugs yet and it's about time for an oil change. It's got stock gearing correct? Also I run 93 octane in mine.

 

Plugs just got replaced with the service. The gearing should be stock, yes. The oil isn't horrible, but I plan on changing it this weekend anyway.

Thanks for the idea Mitch.

 

Vegas i have the same issue. But i believe mine to be fuel pressure regulator cause I have a fuel smell. You said you already replaced yours so that cant be it. Keep us posted on what helps.

 

I get 40 plus no matter what; usually more like 45. Reserve light comes on about 160. I ride like you do. Usually under 5k - Occasionally 8-9k.

 

My completely stock 03 F4i gets 33-35 pretty consistently, whether I flog it or not. 27 seems pretty low considering the type of riding you describe. I wonder if your non-stock airfilter is clogged and making the engine work harder than it has too? Just a thought.

 

That might be worth checking out mmburns, especially since it's so easy to fix. I may do it anyway, whether it actually helps or not.

 

On a recent trip 180 miles round trip I got 49.6mpg. It was about 20 miles of interstate at 75-80mph (one way) and the rest was state hwy and county roads (averaged about 65mph at speed). When I got back home I put 3.75 gallons in the tank. Oh, and I used 87. Better mileage than I thought I would get.

 

I run 93 in mine, and usually get to around 150 miles before my reserve kicks on... On average my rpm's are between 5-6k.