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Mileage dropped 10mpg

4K views 21 replies 19 participants last post by  ScottyDONT 
#1 ·
Did a 17 day long ride out west last month. During the ride my mileage dropped, and seems to have stayed. Was out west and thought might be an elevation thing. Stock 103 engine. Was consistently getting 48-50 mpg. Just filled up tonight for a ride tomorrow, and staying right around 38 mpg now. About to turn over 40k miles on the bike/engine. Doesn't seem to be behaving any differently except have started a small oil leak (think is a return of old leak at clutch cable seal - but not really sure). Just a drop or two after each ride.

Normal, or should I be checking it out??? Thanks in advance.

Ron
 
#3 ·
Best tank I've gotten on my Stage 1 103 was 40 mpg. It's usually 36-38.
 
#5 ·
I have to agree with the others, the only way I get over 40mpg is if I'm on the Hwy cruise control and 60mph, other than that, no way, and I don't normally ride that way.
 
#7 ·
That's close to mine as well on a trip , as long as I keep the cruise under 3000 , it does pretty close to 40 ... When I am planning a trip , I always figger in the amount of gas I think I'll need , I always use 40 as my base and it always comes real close to that afterwards ..

Cruise over 3 grand or wind her up over that and fuel mileage will go to hell fast .. And I usually do both ..
 
#8 ·
I don't think what everyone else gets for mileage is entirely relevant unless he just bought the bike and had expected more MPG. He has almost 40K on it and after this long trip he noticed a 10 MPG drop.

You say it runs fine but want to know if you should check something. It does not sound like you are going to do any harm not checking it but just as you I would be wondering why the gas mileage dropped.

I would at least check the basics.

- Air cleaner (is it filthy)
- Spark plugs are they clean
- Tire pressure / wear

That is where I would start. Although the mileage is not out of line it is lower than what you have been getting for almost 40K miles.
 
#10 ·
This ^^^

While I agree with most that 48-50mpg's sounds higher than normal, it is a bit unusual to see a 10mpg drop. I do keep track of my mileage but only for the reason of noticing a big mpg change if it happens. So to get 48-50 I would say that your bike was running a bit lean and that you are a very conservative rider that rides mostly back roads at slower speeds and no stop and go traffic. Another possibility is that you may have been doing your math wrong but not likely for 40k miles. Did you by chance start riding a bit more spirited on the trip perhaps? The points that suicideshift made could be a large part of the equation, especially the air filter.
 
#9 ·
I recently checked my mileage on a 70-80 mph highway run. Light traffic, occasional 90 mph to pass semis. 40.00? mph.
The only times I've seen 48-52 is on my FXR under ideal conditions, rural roads, 50-60 mph, light throttle.
 
#11 ·
Hey there Ron. When you experienced your mileage drop out west did you per chance get some of that grain alcohol gas? I am on a car forum, some of those folks complain of low fuel mileage when in Colorado due to the E-85 fuel. Is your mileage is better now? If so, it was probably some crappy fuel.
 
#13 ·
I live in Las Vegas NV. My 2102 RGU has 135k miles, Baker DD7 and Stage 1 intake. My Power Vision is very accurate with mileage on IBA rides. 32-38 was my normal mileage. Lately I have been running 3000 in what ever gear I choose riding around the lake. Avg speed is 55-65. I have seen consistent 45 MPG in 100 plus temps. If there is no wind I have hit 50 MPG. On the freeway 70-80 MPH and back down to 35-40 MPG depending on terrain and wind.
 
#15 ·
Thanks Suicide Shift & all. All that stuff is good. I've always thought this thing gets great mileage. I don't think I baby or horse it too much. My buds say if a little quick off the line sometimes but I'm a 62 year old codger :smile:, so I think I'm probably on the conservative side of things. Generally ride at speed limit plus 8-10.

Did a 265 milish loop to the mountains this morning for breakfast. 50/50 interstate & 2 lane. AND my mileage kicked back up a notch to 42. It was ethanol free - which I run as much as I can. I think that definitely gives it a boost.

About to do 40k service soon. Maybe that will help. It's probably just getting some miles on it like the rider. My parts don't all work as good as they used to either! :smile::smile:

Thanks again.

Ron
 
#16 ·
Late to the thread, been searching for this topic. 2016 RGS hasn't had the "Distance to Empty" computer give me less than 300 miles on a full tank since I rode off the dealer lot a year ago (actual miles followed suit). That is until last week. I'd just gotten back from the 12.5k service and turned 13k on the odo. Then--as I started a SaddleSore run at 5am, as I filled the tank and put the cap back on I tapped the DTE and it showed 196. WTFO STFU. Huh?! Not only did the calculated distance drop, the actual distance dropped too! Bike felt and sounded the same, throttle, idle, exhaust note etc. I thought of it all--flat tire, plugs, low oil, clogged intake, heavy load, wind, altitude, bad fuel...none of it panned out. 11 tanks of gas no change. Altitude from 2300 to 7200 no change. No error codes either. What the heck could have happened that dropped my mpg 10+ in a week? Just took it in for the 15000 mile service and my service guys (whom I have a good relationship with) say they didn't find anything, but reset the fuel and 02 sensors and mix mapping for me. Not happy about my loss of range and the service guys wrote "33mpg normal" on my work invoice. ???
 
#17 ·
I think I would do a little homework on 02 sensors. Im wondering If you have one thats going out or something at cruise. I could be completely wrong but if its not working 100% it could be running way rich at times. I really don't know just a thought.
 
#18 ·
Mileage

Well I live out west and the air is pretty dusty. At 25k I pulled my fuel filter and it was BLACK and DIRTY. I know guys have said they never change the filter but out here it is worth the time and effort to change it. A little pain in the ass to do but you wouldn't believe what it looks like . Just a suggestion.
 
#22 ·
That was done at the dealer, twice in 2500 miles, with no change. I think it is a combination of decreased performance in the 02 sensor and lower temps+high winds that contributed. I rode at 55mph in 80 degree weather and magically back up to near 300 miles per tank. It's ridiculous how big a difference these factors are making
 
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