Fuel milage vs Horse power

[V-maximum]

My father in law just purchased a new 660 touring (cat). He rode this weekend with a four stroke venture, a four stroke 1000 bombariter, and a few two stroke triples. when the trip was all said and done, his sled took $13, the venture about $22, same for the big 1000 Bombariter, all others took about $28.
I dont currently own a four stroke sled. But I love power. I'm sure that the Venture would smoke the other sleds (four strokes), but the Venture is lighter than the cat, and has double, almost triple the horse power (120 vs 55) so my question is why would a sled making less power working alot harder pulling a heaver load get way better gas milage than one whose just crusing along?
And why is the Apex with a more advanced lighter package getting less fuel milage than an R-x 1 ton?
:ORC

 

[Wilson]

I ride with a guy that has at660 Touring ,I have 05 Rs Venture .We ride around 100km most of the time . In 400km we were the same on fuel . He uses less when we go slow ,I use less when we go fast . I think the apex is geared lower not sure. Some of these gas mileage differences are caused by how full the tank gets when refuelling .

 

[Mighty]

HP requires more Fuel, period.

 

[vice108]

HP requires more Fuel, period.

What he said.

 

[craze1cars]

Displacement plays a big role as well. It simply takes a larger volume of fuel to fill 1,000 cc's than it does to fill 660 cc's. It also takes more energy to turn the motor that has more cylinders, heavier crank, larger rotating mass, etc....

Much like comparing full size pickups....for years you could get a Silverado with a 4.3L, 5.7L, or 7.4L. All the pickups had similar curb weights, but the 4.3 would get significantly better fuel mileage than the V8's (assuming the trucks are unloaded)

Now to complicate things, you have to consider load on the engines as well. The bigger motor may have some efficiencies at higher loads that the smaller motor does not have. So at 60 mph, that 660 is gonna be struggling hard and probably burning a lot of fuel, while the Venture will be just cruising easy and will do better in those conditions.

This concept was illustrated very clearly on my last snowombile trip. I have a Chevy 6.0 L full size crew cab, buddy has a 4.2 L Trailblazer. On an unloaded highway run, I'll get 15 mpg and he'll get 20. But then we put a 2 place trailer behind each of us and ran them at 75 mph for 600 miles into a headwind....on that trip I got 12, he got 9. His little motor couldn't handle the load and had to burn huge quantity of fuel to keep up the pace while my bigger displacement just walked along fine.

 

[V-maximum]

I do agree with the comparsions made with pick ups. And I do agree that a less powerful engine will work harder at higher speeds or under heaver loads. But what pisses me off is the fuel milage the new yammys are getting with a stat of the art engine(150hp). This engine with less rotating mass and pulling a lighter body should be more fuel efficent than the rx1 peroid !!! I think Yamaha needs to work on their air fuel mixture or mabie a different type fuel injector? This engine should be better on fuel not a PIG. And I know some guys arn't going to like that statment but if I payed $15000(CAN) for a Ultimate four stroke I would be royaly pissed with the fuel milage.
All im saying is it should be atleast as good as the R-X1.

 

[Mighty]

All im saying is it should be atleast as good as the R-X1.

It would if it had the lower HP of the RX-1 8)

 

[APEX 21]

I was hoping for the same mileage with better efficiency of the EFI

 

[GT man]

I agree that the fuel map or something is out of wack. My vector is a light brown color just inside the exhaust pipe. My Gt is blacker than black and I for one am extremely disapointed in the milage.

 

[QCRider]

All im saying is it should be atleast as good as the R-X1.

It would if it had the lower HP of the RX-1 8)

Not true. The difference between the Apex and the RX-1 fuel mileage is much more about reduction gear differences than horsepower. Just because an engine makes more horsepower does not mean you are using it all day long. Two sleds riding along at 50 MPH use relatively the same horsepower to do that. If one of them is spinning 7500 RPM and the other is only turning 4500 RPM guess which one is going to get better mileage!

Thundercats always got good gas mileage because they required very little throttle to cruise at trail speeds, whereas a 600 twin would be pumping much more fuel to keep up. My point is that having more horsepower available to you does not necessarily mean your fuel mileage will be worse. It's how you use it.

 

[V-maximum]

Well if the apex has a gear reduction a little greater than the rx1 than that would mean that it should be easier on gas where the engine isent working as hard. I know its probally reving a little higher mabie 1000 rpm max. That amount and the lighter package should result in a better fuel milage. Yamaha should re-engineer its fuel intake system on the 150 mill.

 

[170plus]

we set my efi up with a exhaust gas sensor in each tube of the header ,from the factory it was quite lean,almost to the lowest point on the chart,we set it up so its running about 1/2 way between the lowest and the highest setting as far as the air/fuel ratio goes,i believe it is 12.5-14.5 but dont quote me on this,we set mine at 13.4-13.5,im getting 18.5 on good trails and down around 16 on soft new snow conditions,hard running with the boys i get around 15.5,since about 700 miles i have never gotten below this,i think it would be better on fuel set down to around 12.5 but would i still run as strong as i do now ?from what my dealer said ,every sled is a little different from the factory,one might be way out of sync and one might be really close and same for fuel settings,mine were all even at factory settings(0,0,1,0) from injector 1 to 4 and the next one they checked was (-2,7,5,-7) on the display

 

[V-maximum]

What ever happened to yamahas top of the line quality? Every sled should be atleast close, not off by that many points on their fuel rail adjustment. [/quote]

 

[170plus]

its the injector manufacturer that makes the difference not yamaha,cars are the same way,go buy a set of new injectors off the shelf and they all will flow a little different,i think you'll see an easier way for dealer to check and adjust the efi in the future,gotta make it easier than it is to make sure these things are running to top performance