Real fuel economy??

[RX3James]

Ok everyone what are you really getting on your RX3? I typically fill my tank as full as I possibly can. After a 68 mile group ride last Friday morning and riding back and forth to work all week I traveled a total of 101.8 miles. I put in 2.955 gallons of premium today topping it off.. so after some quick math I'm averaging 24.23 miles per gallon.. how is that even possible? I ride very conservatively and I don't hot rod around town.. I've done one oil change and the valve adjustment. I've always used premium fuel and there's only 940.9 total miles on the bike. So what's up? Did I just get the one and only gas hog RX3? I'm kind of upset that I'm getting less than half of the advertised MPGs.. any suggestions to improve my fuel economy?

[Danimal]

101.8/2.955=34.55 mpg

still low.

I seem to be averaging around 58mpg or so on mine.

[RX3James]

You're correct it should read 34.55 MPGs.. Still less than half of the advertised 70 MPGs. I cant for the life of me figure out why im getting such poor fuel economy. I take really good care of the bike and like I said before I ride very conservatively. So who knows...

[NoVa Rider]

Obviously something's not right. How does it start and run? Is oil level holding steady? Any signs of black smoke from the exhaust?

First thing I would check is the air filter. Any sign of blockage? Maybe too much oil on the filter? If that looked OK I'd take out spark plug and check for rich running. And at that point I would give CSC a call.

[SpudRider]

I average about 68 mpg, which is about twice the gas mileage you are getting. :shrug: I think NoVa offered good advice; I would do as he suggested. ;)

[Lee R]

55 average for me. Best I've seen is 58.

[SpudRider]

58 mpg is the worst gas mileage I've recorded. However, I ride conservatively. ;)

[Weldangrind]

Obviously something's not right. How does it start and run? Is oil level holding steady? Any signs of black smoke from the exhaust?

First thing I would check is the air filter. Any sign of blockage? Maybe too much oil on the filter? If that looked OK I'd take out spark plug and check for rich running. And at that point I would give CSC a call.

X2.

Just spit ballin' here; perhaps an O2 sensor that is on the way out might not yet have triggered a code, but it could be causing the PCM to dump too much fuel in.

Also, does the bike require premium? I'd challenge the notion that premium would result in higher economy, if the bike only requires 89.

[Lee R]

It doesn't require premium and you won't see any benefits.

We do have non-ethanol at all the Stewarts shops around here which is what goes in both my bikes. You do get better mpg with non-ethanol.

[Weldangrind]

That's what I figured. What does the manual recommend for octane? Does it specify R+M/2?

[SpudRider]

That's what I figured. What does the manual recommend for octane? Does it specify R+M/2?

Page 6 of the Owner's Manual specifies the following.

Fuel: Minimum 87 Octane

However, the white sticker, placed on the left side of the frame next to the triple tree, specifies the following.

Fuel: Unleaded Gasoline - 91 (R+M)/2

[SpudRider]

I was burning regular fuel, which is 85 (R+M)/2 at Great Basin elevations. However, Gerry recommended a higher octane, so I switched to 87 (R+M)/2, which is the fuel I burn in my Honda CRF250X.

https://en.wikipedia.org/wiki/Octane_rating

https://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Gas_Station_Pump_Five_Octane_Ratings.jpg/280px-Gas_Station_Pump_Five_Octane_Ratings.jpg

[RX3James]

The bike starts and runs with no issues. The only thing that I've noticed is that at times it runs pretty hot. 4 bars is fairly standard for a normal day of riding around SoCal. I'm going to take a look at the air filter and the spark plug today and see what they look like.

[RX3James]

Forgot to mention the oil level is holding fine and there are no signs of black smoke or anything like that. I haven't seen anything on the instrument cluster indicating any fault codes. As far as running premium.. it's just something I've always done with my motorcycles. Just force of habit I guess..

[SpudRider]

The bike starts and runs with no issues. The only thing that I've noticed is that at times it runs pretty hot. 4 bars is fairly standard for a normal day of riding around SoCal. I'm going to take a look at the air filter and the spark plug today and see what they look like.

When the engine is cold, make sure to check the coolant level. Also, keep the overflow bottle full, until the coolant level stabilizes. Most of the RX3 bikes are low on coolant when shipped from the factory. The routing of the radiator hoses tends to leave an air bubble in the left radiator. ;)

[RX3James]

I checked the coolant reservior level and it was below the "L" so I topped that off. This is the second time that i've had to fill it up. I looked into the right side radiator and it was plum full so i'm hoping that i've got the correct coolant level now and the bike will run much cooler. I checked the air filter and the spark plug. Both look good. I guess i'll just run a few more tanks through and keep crunching the numbers to see what I get. If it doesnt improve i'll be giving CSC a call and asking them to take a look at it.

[SpudRider]

Even after the radiators are full, the coolant level will drop slowly. I suspect the coolant evaporates slowly from the overflow bottle. ;)