i have seen numerous posts on here about gas mileage and everyone seems to be getting way better than me. Im lucky to get 110 miles before hitting reserve. 42/125 jets, D & D's. stock airbox. I dont ride really agressively, but am not over easy on the throttle either. is this normal in your opinions or could there be another factor in my poor gas range? I have also been considering a 18/19 tooth sprocket to help this problem. With gas prices the way they are i did the math and its actually cheaper to drive my car than my bike. :???:
If i had to take a wild guess it would be that with D&D's and richer jetting, not improving the air intake might be leaving you rich and therefore using more fuel and NOT gaining the power you would if the airbox was opened up some. If you did that and gained more power you'd basically be getting more accelleration per amount of gas used and therefore need to twist the throttle less to get the same performace you do now for the same riding style you do. Thats just a guess, but seems like a possibility.
> i have seen numerous posts on here about gas mileage and everyone seems to be getting way better than me. Im lucky to get 110 miles before hitting reserve.
So *** is your <u>actual</u> gas mileage????
And I don't mean some flaky guess about what you have left in the tank at reserve, either. How many miles from one fill-up to the next, and how many actual gallons did it take to refill?
You get 110 miles before reserve when most of us get 125, or for some a little more. That's not a huge difference...just a little over 10% less than what I get, when my actual measured MPG is in the high 40s to about 50.
I don't know what sort of "math" you're doing, but unless your car is getting in the low- to mid-40s MPG, or unloess you're giving the bike high octane for no good reason, the bike is not costing you more for fuel.
ok Diego, *** do seem to have such an attitude for, no need to for man. my last two fill ups are 123 miles with 3.2 gallons, 38 mpg, and 120 miles with 3.25 at 37 mpg. thats my math. and i get 320 miles on 10 gallons in my honda. thats 32 miles per gallon on regular 87 gas which there fore is roughly the same money spend
On 2006-04-29 13:55, Diego wrote:
So *** is your <u>actual</u> gas mileage????
And I don't mean some flaky guess about what you have left in the tank at reserve, either. How many miles from one fill-up to the next, and how many actual gallons did it take to refill?
I agree, need some more specific data. FWIW, my America (Specialty Spares/Uni/No snorkels/ 44/132.5 jetting) gets between 41-43 mpg. Don't think I ever went past 44 mpg. I sync'd the carbs a few weeks ago. They were WAY off but syncing didn't seem to have any effect on my MPG.
Unless you are in the mid 30's, I'd say that is just the normal range.
Because the last time we had a question like this, the thread rambled on for nearly four pointless pages because the guy had not done and would not do the real math, but insisted on making assumptions about what he had left when he switched to reserve. This can vary enough from bike to bike to make comparisons and assumptions utterly meaningless.
I gladly give you credit for having done yours, and I appreciate seeing the numbers. My apologies for jumping to conclusions about how this was likely to proceed.
It does seem 37 and 38 miles per (US) gallon is a bit low. And using 89 octane in the bike versus 87 in the car would indeed make up the dollar difference. I'm inclined to agree with Daz that you may be running richer than you need to with those jets; don't know what sort of shims or additional adjustment you're running with them, but a bit of tweaking might give you better mileage while keeping your performance.
an incomplete list to check
is either brake binding? are you resting your foot on rear brake pedal.
spark plugs ok with correct gap.
check emissions to ensure not running rich.
check air filter is not clogged
choke works, (especially disengages properly) and you ride from starting without idling with choke in. ie ride as soon as it starts.
switch of petcocks before stopping engine at end of ride.
Some engine management systems 'learn' so if you have put in dose of poor grade fuel, it will continue to run retarded when the new good stuff goes in. ( do not know how triumph system reacts, may not apply )
It has been my experience that poor economy is usually due to the engine management system.. Not the electronic one under the tank , but the bio one at the end of your right arm. ride smoothly, do not jerk on the chain. Mount a plastic cup of liquid on your bike and try to keep as much as possible in the cup as you ride....( for practice only) will detect and display sudden changes that are fuel consuming.
UHOH, I think I've been resting my foot on the brake pedal. I was very conscious of it when I first got my Bonnie, but have relaxed a good bit since. Thanks for the list. Also, thinking about it, my bio engine management system definitely needs adjustment. The message center has been pulsing my right arm for greater acceleration much more frequently. :-D
I think any gas mileage figure for me is useless until out on the highway with some consistent speed over time. In town is so erratic, stop, go, passengers, no passengers. Can't wait to get away!
Dennis
[ This message was edited by: wonderdog on 2006-04-29 16:53 ]
Just turned 200 on my new Bonnie. Filled up this morning. Figured out to 47 mpg. Have not run it down to reserve.
Been running low rev's since just in breakin
No mod's,......yet........
Will be dropping down to 89 octane instead of the 93 been using.
Much nicer putting gas in the Bonnie than in my F250 Diesel.
Trav:
Since I don't modify my engine I have no CURRENT experience on what your particular mods do to your mpg. BUT, almost all the mods I see listed here are bound to increase fuel usage; a trade-off for real, or maybe even perceived, performance improvements. In my younger years when I was into engine mods and misc. tinkering I can't remember one time when modifying the bike to improve performance actually improved mileage.
I'm not sure what a stock Bonnie should get, but I have been getting about 50+mpg locally, mixed road and street riding. Until today I had not tried much distance on the interstate but put 102 miles on I-77 running an indicated 70-75 the whole trip. I thought it would drop the mileage quite a bit, but it didn't. I got 49.97 mpg on the run. And it isn't even broken in yet, about 470 miles on it now.
Unless someone can show me where I am wrong, I would say that if you want higher mpg, don't modify. Or, if you want really good mileage, get a nice 125-250cc scooter and get around 65-85 mpg.
my initial post is basically in response to other prior posts about gas mileage wherein people with the similar mods seem to be getting better gas mileage. before i modified my bonnie i was getting at least 130 miles before switching to reserve.
I have generally gotten 38-42 mpg on ALL my bikes, it's the way I ride. However I've also seen as little as 28-36, and as much as 48-56..... on 1,000cc + bikes. Same as held true on my little 790cc Bonnie in it's various states of mods.
I recently re-jetted and ran with and without a shim. Without the shim it coughed, spat, and sputtered at the point that I was neither on nor off the throttle. All that I did was remove the shim!?!
So I put it back:
Straight through pipes w/minimal baffling
restrictor plate removed
designer NH bellmouth & K&N
42's, Thruxton needles, 1 shim, 130's
Imagine my surprise when on a 150 mile freeway run at 68-75 mph, with sprints up to an indicated 95 mph, my set-up returned me 50 mpg?!!!!!! For the past 13,000 miles, I've grown accustom to seeing 38 to 42 mpg.......
I'm now convinced that it's not only about how you ride, but it's about the state of your tune AND (with a carbonated engine) fuel delivery..... the jetting.
The final factor that needs to be mentioned though is an anomaly characteristic of .22 guns and two cylinder engines. Twenty-two caliber guns have an affinity for a very specific brand of ammo, and it takes a lot of experimenting to find the stuff that it likes.... very weird and not easily explained. Two cylinder motorcycle engines each and in their own way have unique and potentially differing characteristics. Two identical T100's side by side, can return not only very different performance figures, but different gas mileage figures too..... with the same robotic rider. (?!?!?!) So with .22 guns and T100 fun, no two can be expected to be alike.
One main reason is probably city driving. On the freeway I get 50mpg. My morning ride to work in LA I get 35mpg average. When I lived in San Fran I got 29-31mpg average.
On 2006-04-29 21:13, trav13 wrote:
my initial post is basically in response to other prior posts about gas mileage wherein people with the similar mods seem to be getting better gas mileage. before i modified my bonnie i was getting at least 130 miles before switching to reserve.
Your 38 mpg isn't too far off the mark. I complained about a drop in MPG after adding exhaust/rejetting to my daughters boyfriend, a Yamaha/Kaw tech. He said "you went larger on the jetting, right?". I said "yep". He replied, "so you EXPECTED to use LESS gas?". I slunk away.
I hear of guys getting in the high 40's and guess there is just a range of results with this motor. I am also running the 18 tooth front sprocket, btw.
This is a bit silly: I achieved 36.8 MPG with my Honda Accord (4 cylinder, Auto) and get 40-42 on the bike. The bike is a bit more fun to ride though. <g> My HD buddies get a lot closer to 50 mpg, with one carb or fuel inejction.
I'd try setting the carb air/fuel mixtures slightly leaner, see if that gives any result (didnt' on my bike, currently at 3.25 turns out)
To my mind, common sense says that all else being equal, it's how efficiantly the engine uses it's fuel that makes for best milage. Not whether it's got airbox mods pies and bigger jets. If 2 guys ride side by side in a normal fashion on identical bikes that are both perfectly jetted but one has air mods and pipes, the way i see it MPG should be very close. A modded bike will indeed eat more gas when you take advantage of the extra power, but otherwise i don't think it would make for very low mpg compared to a stock version. But today i may be going for a long ride where i may be hitting reserve. I always set my odo to zero when i gas up as i did last time, so if i do hit reservei'll check the mpg against the last time i checked it which was BEFORE i did any mods. If i do that today i'll post back with the results. The only problem is the area i'm riding is mountains and i'm not sure i'll be able to work it out so that i hit reserve when i'm NOT in the middle of nowhere with no gas stations near by.
Well, i took that ride i mentioned and ran out at 130 vs the 140 i got before the mods. BUT, when i tested it before mit was all city/highway and a mixture of slow riding and a bit of twisting the grip. Today however it was lots of uphill Mt roads and LOTs of twisting the grip. So while i got 10 miles less before hitting reserve i'm sure had i been riding noramlly on level roas it would have been at least 140. So i don't think the mods hurt my milage at all. Maybe even a bit better because as hard as i rode that 130 miles i figure i should have lost more than 10 miles per tank. (at reserve of course)
Unless someone can show me where I am wrong, I would say that if you want higher mpg, don't modify. Or, if you want really good mileage, get a nice 125-250cc scooter and get around 65-85 mpg.
a basic way to get higher mpg, is to increase compression ratio, then strangle it a bit with a smaller diametre carb. I am not entirely sure it would work with today s***** petrol
For what it's worth, my Bonneville's mileage varies considerably based on the kind of riding I'm doing. If the only riding I do on a particular tank of gas is in town, I'll invariably have to switch to reserve around 110 miles (35mpg). But spending a day riding around the Vermont countryside, I've gotten over 150 miles before having to switch to reserve (50mpg). This is with a stock airbox and TORs, btw.
--mark
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Triumph Rat Motorcycle Forums
3.9M posts
167.7K members
Since 2002
A forum community dedicated to Triumph Motorcycle owners and enthusiasts. Come join the discussion about performance, racing, cafe racers, bobbers, riding, modifications, troubleshooting, maintenance, and more!