On the 09 zx14 I kept the front 17 tooth sprocket and went up 2 in rear to a 43 tooth sprocket average mpg was 32mpg, knowing I'm using a lil more higher rpm at highway speeds, I assumed I could get better than 32mpg by going back to the 41 tooth rear sprocket which would lower rpms a little while cruising, eh no dropped to 29mpg after the 1st half tank, what the hell????

If you're using the onboard computer to determine the fuel mileage, it will probably be off now (not sure if a speedo-healer will help or not). You're best off just doing the math at the pump, reset your tripometer, go out riding, fill up, take your mileage divide by the amount of fuel you put in and vola, your MPG.

My bike was off by about 10% when I actually calculated the mileage.

Zoom if you riding a ZX14 and worried about fuel miles buy a Ninja 250....lol I'm sure you'll get 50 MPG outta that moped....

Nightmare I use a mileage app on my android which i put in the odometer, gallons put, and price per gallon every fill up and it averages it out. Worried? no I'm not worried, I got 42mpg with the +2 on a 3 hour ride, I know what its capable of, which is doing better than 29 somefun

If you're using the onboard computer to determine the fuel mileage, it will probably be off now (not sure if a speedo-healer will help or not).

A speedohealer or bonneville will correct the speedo and odometer so that should be all you need if you are using the the bikes odo to make the mpg calculation.

It's too early for me to do the math but I would expect the fuel mileage to be off a little. different sized sprockets cause the speedo and the odo readings to change from what they had been. My 45 T rear with 55 tire is about a 13% change from stock.

I think I get about 30-35 mpg???? I can go about 140 150 miles on one tank depending on how high I fill it.... But I don't really care. Like Kolfa said, it's a big sport bike. The fueling is changed, the gearing, the exhaust, ....NOS pretty soon, I imagine that will cause a small drop in fuel economy!

* Last updated by: Rook on 1/22/2014 @ 7:53 AM *

just figured mine out and I get roughly 24.5 mpg with my 08.

24.5mpg?? I think I heard the planet cry a little bit on that one ;)

I was getting ~37mpg on my 08 before I did my mods, now I'm getting 48+mpg with stock gearing & tires (calculated using onboard tripometer). While I agree with Somefun, that I didn't buy this bike for fuel economy, getting better gas mileage than my car helps to justify the cost of owning the motorcycle.

Exactly nightmare, you said it best, I sure as hell can't get on myduramax what I get on my 14. "Justify the cost" maybe I can get to 48+ now that I'm back on stock sprockets and 50 series rear tire as I got 42 mpg with the 190/55 and +2 rear sprocket

When I had 16/43 on my 07...and a Jeffo map with PC3 and aftermarket cans,I could pull down 34 mpg routinely.Stock(gearing) and the Jeffo deal/pc3,38-40.Depending.29 sounds really low.You don't have a manual timing wheel on there do you?How's the air filter?

* Last updated by: Grn14 on 1/22/2014 @ 11:34 AM *

Grn14 is that with 93 octane gas? No manual timing chain added. I installed the k&n filter last year, I'll check it. How often do yall re oil the filter?

Zoom, looking at your signature, I noticed that you've got quite a bit of mods on your bike, even though you have a map by a reputable tuner it doesn't mean the map is perfect. While the smaller rear sprocket lowers the cruising RPM, it might have actually put you into a throttle/RPM range that is less fuel efficient.

I decided to get a auto-tune module for my PCV as I thought the map I had was a good starting point but could use some tweaking, it ended up making a huge difference with better throttle response, off idle response, and fuel economy.

Nightmare, that thought did slip my mind about it going into a less fuel efficent range, I told a friend maybe my transmission has to re learn the sprocket setup again

I run A 16/42 combination with a Super Sport head ported n polished with 47 mm throttle body's and still get 32 to 34 miles per gallon....

Yeah man looking at your mods with the gearing change and with the extensions your odo readings are not going te be any where close to stock readings.... you'll need a spedo healer to get close to correct readings on odo. the extensions also modify the efects of the gearing changes.

Yes.

You were probably only getting 29 MPG with the 43 tooth set up also. For example, with the 43 tooth rear sprocket say your odometer reads 100 miles you really havent gone a hundred miles as the odometer doesnt know the different sprocket is on. So you take 4 gallons at fill up and you get 25 MPG. But you really have gone less miles so your average MPG is false and will read high. With the 41 tooth on, now you have actually gone 100 miles so you will have used more gas and your MPG will seem lower even though it isnt. Does that make sense?

I follow what you're saying streetracer. I ordered a muzzy bonneville pro, now I should be able to get my mph on the dash ON POINT, I believe everything on dash and hand calculated should match once its set right

Regarding how often to clean and re-oil your filter... it depends on where you live, its pretty dusty here so I usually do mine when I change the oil on the bike, I think K&N calls for every 10,000km.

Also, Streetracer, if your odometer is overestimating your miles traveled (ie, it think you travelled 100 miles, but you've only gone 80 miles) when you goto fill up with fuel you'll probably need less which would show better mpg. However, I agree and think this might be the main reason why the mileage isn't correct.

Zoom, if you can get an accurate distance reading and fuel consumed I think your numbers will be a lot better than you think.

I feel I need to ride harder if I get too many miles per tank

Zoom, my set up is similar to yours. 2009 ,2 brothers 4-2-1, K&N filter, flies out, PCV with Jeffo map, 16/43, Speedohealer set with GPS and I am in SETX. I was getting 28to29 MPGs. I removed my PCV with Jeffo map and now get 33 MPGs.

O6blue14 did u ride that 78 gold wing hard?? Dericrey u took the power commander off? And got 33 with 16/43 setup? Are you stretched? Y would u take the power commander off tho, u don't think she performed better?

Zoom, yes I am running 16/43 and getting 32.5 to 33.2 miles per gallon. No stretch but I run a 200/50 rear tire on stock rim. I think it performs better without the PCV, at least using the canned maps (never had a Dyno tune). It certainly gets better gas mileage now and the exhaust doesn't smell near as rich, decel pop is less also. I imagine my plugs will be cleaner without such a rich map. As far as the seat of the pants feel, I can tell no difference. The front end pulls up at will as before PCV.

Dericrey, I'll try the disconnecting option. If I ever want to reconnect it do I have to reprogram the power commander?

The map is saved to flash memory on the power commander, so you wouldn't need to reload the map when you reconnect it. I'd caution removing the PCV, the stock map on the ECU is made for stock parts, there's a good chance that you'll be significantly leaning out the mixture to the point that you could start doing engine damage. You are MUCH better off using an auto-tune to fine tune the map.

Wouldn't want engine damage, thanks for the heads up nightmare.