Gas mileage?

[themeatmanlandry]

Originally Posted by Tab B.

I've found with casual observation that many riders on sport bikes run around in a gear or two lower than what they need, to cruise. If you are in an aggressive mood, then obviously be in the gear, and RPM, that give you the power delivery that you want. In that mood, don't expect your bike to sip gas.
I listen to lots of sport bikes cruising through town in 3rd or 4th gear, when they could easily be in 6th, that is regardless of engine size. The speed limit through my town is 30mph. I get consistent 45 mpg with my modded gixxer on the street, mostly because I have paid attention to the lowest speeds the bike will tolerate in high gear with out lugging or pinging it to death. I can short shift my engine and be in 6th by 30mph, and on my bike, since the tach starts at 3000rpm, I can do it without nudging the needle. That is where you get good mileage. You have to consistently have your pistons travel the least amount of feet, per mile traveled. I call it surfing the bottom of the torque curve. I know every bike is different, but lots of people don't try to find their bike's real low end capabilities. Obviously, acceleration when you are doing that stinks, but I do it when I don't need, or just as importantly, don't want the acceleration. If I am in traffic, I'll accelerate as needed to keep people from climbing up my butt. If I'm not, and I'm not in a hurry to get anywhere, or feeling rambunctious, I'll short shift. The other benefit besides better gas mileage, is your engine lasts longer.

Good approach. I read Car and Driver a lot (not sure why since Brock Yates "retired" ) and they claim that the "Golden Rule" of gas mileage is RPMs. The least number of times you draw the air/fuel mixture into the chamber for a given distance traveled, the better your fuel efficiency. Very simple.

The last sentence can be debated. I've heard (mostly from car guys) that an engine running near idle doesn't supply as much oil as it should, due to decreased oil pressures.

I honestly don't know enough to discuss it.

[Tab B.]

Originally Posted by themeatmanlandry

The last sentence can be debated. I've heard (mostly from car guys) that an engine running near idle doesn't supply as much oil as it should, due to decreased oil pressures.

I honestly don't know enough to discuss it.

Don't worry, neither do I. But what the heck. When I short shift, at least on the gixxer, I am far enough away from idle, oh say, about 2000-2500 rpm{guessing because of the tach}, and I'm doing it under very low load conditions, that I don't worry about lubrication issues. Doesn't mean there aren't any. With my GSX1100G, on the other hand, that might be something to consider. The torque curve, and gearing on that bike, will let me get it into 5th using 1500-2000rpm. I have even let it drop down to 1000rpm {on the tach} in 5th, and with the gentlest of touch, it will pull from there without audible complaint. That isn't something I make a habit of. But I think you get my gist. Modern sportbike engines are extremely flexible and tractable.

[JmalB]

Originally Posted by themeatmanlandry

Good approach. I read Car and Driver a lot (not sure why since Brock Yates "retired" ) and they claim that the "Golden Rule" of gas mileage is RPMs. The least number of times you draw the air/fuel mixture into the chamber for a given distance traveled, the better your fuel efficiency. Very simple.

The last sentence can be debated. I've heard (mostly from car guys) that an engine running near idle doesn't supply as much oil as it should, due to decreased oil pressures.

I honestly don't know enough to discuss it.

Sounds fishy. I'm not completely knowledgeable on the subject either, but that would mean that any time the vehicle is idling or near idle, it isn't getting enough oil. So it's not getting enough oil while sitting at traffic light?

[Clint]

No, the implication is that while under load and near idle the oil film isn't adequate. There's a tremendous difference in shear and compression force.

[old codger]

"One thing that has been bothering me is gas mileage. I get about 130 out of a tank, the previous owner promised me upwards of 60+ Miles per gallon, Was this an empty promise or should I have the bike serviced? "

To figure gas milage divide the miles ridden by the fuel used, to get a more accurate milage figure take the miles from 3 tanks divided by the fuel used. This will average out the different fill levels at each fuel stop.

You are not likely to get 60 MPG from a sport bike no matter how you ride.

Old Codger

[themeatmanlandry]

Originally Posted by RowdyRed94

No, the implication is that while under load and near idle the oil film isn't adequate. There's a tremendous difference in shear and compression force.

I'm glad you knew that, 'cause I was honestly stumped. I had no answer.

I usually go on what I'm told/have heard. It sometimes creates problems.

[MikeHump]

I have an 07 gsxr600 and I only seem to be getting about 33 mpg. I shift early, and ride around town in 6th most of the time. It's my first bike so I'm taking it really easy on it but I still don't seem to be getting the gas mileage that was claimed (40-45). I also know that lugging the engine is very bad for the bottom end, so I try not to shift too early. I generally keep it around 3500 rpm. Should I be getting better gas mileage?

[Clint]

Yes, you should. That's odd. Sounds like you're doing everything right, though 40-45 is usually a highway number. Stop-n-go will never be that good.