Fuel Mileage Per Tank?

#1
Hi there, I'm new to the forum and I recently purchased a new to me 2005 Bonneville Black. The bike has 5,500 miles on it and I mostly ride it around town for commuting in Boise, ID. When I received the bike in early June, there was some gas in it and I topped the sucker off. It made it to about 120 miles until it had to be switched to reserve. On the next tank of gas, the bike began sputtering at 99-100 miles before switching to reserve. On my most recent tank of gas (fill up #3) it sputtered at 109 miles before I switched to reserve. Between the 1st and 2nd tank of gas I changed the spark plugs, oil & filter, and adjusted/cleaned/lubed the chain. I found it to be interesting that the mileage seemed to go down significantly. Since I'm new to riding the bike, thought I would ask if this sounds like a normal fuel mileage range? Should I be worried about the drop from 120 mi to 100 and 109 mi before reserve?

Oil Used: Mobil full synthetic 10w40
Oil Filter: K&N 204

Other than switching the oil filter and plugs, the bike is completely stock.
 
#2
Since the bike is barely broken in your mileage will vary. But the big factor is the stop + go in commuting traffic. Check your air cleaner it could be dirty after all those years. Also you may want to run a couple of tank full of gas with Sea Foam. which is avail at auto parts stores, Lowe's, basically all over.
After all that is done your mileage may not improve that much. My 05 T100 would get about 125 miles before I'd switch to reserve. Enjoy your bike and don't forget to reset your trip odometer.
 

bonZa

Street Tracker
#3
miler per gallon varies a lot with these bikes

short trips of a few miles then restarting a cold engine and another few miles they guzzle.

if they havent been ridden often they guzzle, probably due to some fuel evaporation

long steady rides they are ok

in US gallons per mile mine ranges from 38 mpg to 45 mpg
usually I have to switch to reserve between 130 miles to 150 miles
it does sound like yours is using too much fuel
 

rbirkey

NBRAdmin
Staff member
#4
I have a seriously modified Bonneville with an 1100cc Bonneville Performance race engine. Even with all the modifications, I get in the low 30 MPG around town, and the low 40 MPG on the highway... running premium gas. The more efficient your engine is at burning gas, the better mileage you will get. You may want to check your spark plugs and the gap to be sure they are in spec. As was already mentioned, check to be sure your air intake is unblocked and free-flowing. There is a baffle inside the stock airbox, that can be removed, and you can get more free-flowing air filters from K&N. You can also consider a less restrictive exhaust system, either Triumph Off-Road mufflers (TOR's) or some aftermarket silencers like the Norman Hyde Toga's (which I really like the sound of).
 
#5
Thanks for all the advice guys! I've put some Sea Foam into the bike and have been running premium gas. Nothing to do, but wait and see how it does with my riding style.
 

OFC

New member
#6
Hi there, I'm new to the forum and I recently purchased a new to me 2005 Bonneville Black. The bike has 5,500 miles on it and I mostly ride it around town for commuting in Boise, ID. When I received the bike in early June, there was some gas in it and I topped the sucker off. It made it to about 120 miles until it had to be switched to reserve. On the next tank of gas, the bike began sputtering at 99-100 miles before switching to reserve. On my most recent tank of gas (fill up #3) it sputtered at 109 miles before I switched to reserve. Between the 1st and 2nd tank of gas I changed the spark plugs, oil & filter, and adjusted/cleaned/lubed the chain. I found it to be interesting that the mileage seemed to go down significantly. Since I'm new to riding the bike, thought I would ask if this sounds like a normal fuel mileage range? Should I be worried about the drop from 120 mi to 100 and 109 mi before reserve?

Oil Used: Mobil full synthetic 10w40
Oil Filter: K&N 204

Other than switching the oil filter and plugs, the bike is completely stock.
I am Spanish. I bought a 2005 T100 with 33.000km It is in perfect shape and a full tank last 100 miles (160 km). I think that the new T100 EFI are much more eficient than carb but that's it. A carb is a carb. Enjoy it and do not wory.
 
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