fuel economy taking a hit

[jimmy z]

When mine was new the best I got was 48-49mpg, having too much fun with it now and my average has been 42-43.
I’am thinking about a flash but I’ll bet that will bring it down to what my FJR was getting. 38-40.

Adding a flash does not decrease fuel mileage unless you drive it harder after the flash.

 

[Cdutch]

I flashed mine and adjusted fuel tables (more fuel 5% at 2500-3500 rpm) lost maybe .1 gal per the readout.
Was 43.4 now 43.3

 

[2daMax]

Give it a Fuel system cleaner to clean up the intake valves and injectors. The carbon deposits on intake valves is not a myth.

Do checked all the vacuum related areas, such as the TB boots, RHS TB rubber plug, MAP sensor rubber hose on LHS TB.

How is your battery condition? If it reads anything below 12.4V when bike is off (after settling down ~ 1 hour), it is an indication it is weakly charged. (try charging it up or new battery). Also, check the cable connection at the starter relay and battery terminals. Some reported loose connections.

 

[tallpaul]

I've "been told" that the gasoline in the UK is of higher quality, or octane, than the US. True? False?

It's true from an octane perspective. Our regular unleaded is 95 octane. Most suppliers offer a "super" unleaded that is between 97 and 99 octane depending on who's you buy. I have been using Tesco 99 octane super but read that you can have too much of a good thing. The bike was set up for 95, so that is now what I fill it with. The only difference I've found is in my wallet as the 95 is cheaper...!
Edit: for giggles I just checked the cost of our fuel against the dollar rates. An imperial gallon (4.54 litres) works out at £5.72 or $7.30 at $1.28/£1.
A US gallon (3.8 litres) costs us the equivalent of $6.20. How's that compared to you guys?

 

[magic]

Winter fuel is partly to blame for the mileage drop. Cold air is denser than warm air creating more aerodynamic drag on your bike, car or truck increasing your fuel consumption.

Tallpaul, gas is about $2.35 a gallon here in Wisconsin. That's for 87 octane, 10% ethanol, "regular". 91 octane 100% gasoline is about $2.85 the last time I looked. It's been winter around here for about a month already.

 

[RCinNC]

The UK and the US don't use the same octane rating system. What you're buying in the UK as 95 octane fuel would be 91 octane in the states, which on the eastern seaboard is sold as mid-grade. "Premium" grade fuel in the east where I live is 93 octane, which would be equivalent to your grade of 98 octane. Europe uses the RON (Research Octane Number) system, while the US uses the PON system (the Pump Octane Number, which is the average value of the Research Octane Number and the Motor Octane Number).

A gallon of premium (US 93 Octane) is currently about $3.11 a gallon where I live. Regular gas (87 Octane) is about $2.49 a gallon. The price varies quite a bit from state to state (and even county to county) based on transportation distances, taxes, and other factors.

There's a myth that high octane fuel is somehow "better" than lower octane fuel; probably because here in the US they call it "premium". Guys will talk about how they "treated" themselves to a tank of premium. I believed the myth myself at one time in my younger days. Putting high octane gas in an engine that doesn't require it is just a waste of money.

 

[tallpaul]

Thanks RCinNC for the clarification on the relative octane ratings. I didn't know about that, so learned something. I still want your fuel prices! They look to be about half or less of what we pay.

 

[Sierra1]

....A US gallon (3.8 litres) costs us the equivalent of $6.20. How's that compared to you guys?

Holy s**t!! Locally, here in the Ft Worth area, we're down to $1.98/US gal. But that is 87 octane. 91 octane, the highest I can find, is 20-30 cents more. Yes....we are spoiled. Cheap gas and great weather....a motorcycle's best friends.

 

[Nikolajsen]

Denmark, is just about 6,5$ for a gallon. (similar to tallpaul, and the rest of scandinavien (Norway, Sweden and finland))
In Denmark about 40% of the price goes to the company where you buy your gas, the rest if tax.

 

[tallpaul]

Yeah, "green" taxes because of global warming. Snag is, the last ice age was 2.5 million years ago and there were no politicians around to tax anyone for the rising temperatures...! Ok, I'm being flippant. Still like to have a mini rant every now and then!

 

[RCinNC]

Thanks RCinNC for the clarification on the relative octane ratings. I didn't know about that, so learned something. I still want your fuel prices! They look to be about half or less of what we pay.

You're welcome.

To be honest, I don't rigidly adhere to the premium fuel recommendation for the Super Tenere set by Yamaha. I use 87 octane fairly often. The engine runs fine on 87, and I've never encountered any issues with predetonation. Big chunks of the world don't have premium fuel, which would make this a big limitation on a bike with the word "worldcrosser" figured into its advertising. Nick Sanders, who I pretty much defer to on matters of extreme usage of these bikes, routinely encountered sub 87 octane fuel in his travels. After his Alaska to Tierra Del Fuego and back to Alaska ride he had his engine torn down after 50,000 miles, and the engineers found virtually no signs of damage or excessive wear. That was after running on fuel as low as 82 octane.

Conversely, I used to ride a Harley Road King, which would ping like crazy if I ran it on anything less than 91 octane. I had some problems out west, where 91 wasn't always available and 89 octane was the highest. There were times I had to add an octane booster to the tank of fuel to stop the pinging on 89 octane.

 

[HeliMark]

It's true from an octane perspective. Our regular unleaded is 95 octane. Most suppliers offer a "super" unleaded that is between 97 and 99 octane depending on who's you buy. I have been using Tesco 99 octane super but read that you can have too much of a good thing. The bike was set up for 95, so that is now what I fill it with. The only difference I've found is in my wallet as the 95 is cheaper...!
Edit: for giggles I just checked the cost of our fuel against the dollar rates. An imperial gallon (4.54 litres) works out at £5.72 or $7.30 at $1.28/£1.
A US gallon (3.8 litres) costs us the equivalent of $6.20. How's that compared to you guys?

Okay, have calculator, annnnd you will not like me. If you payed what we do in Texas, it would be (converted to imp gallons):

£1.83 per gallon for regular
£2.29 per gallon for premium

 

[Cycledude]

I’ve ran regular gas in the Tenere a bunch of times because premium was not available and never noticed any difference other than price.

 

[Tenman]

I don't buy into the winter blend reducing mileage. I've had a bunch of vehicles that get the same mileage in winter.

 

[SHUMBA]

Oh forgot to add ethanol to mix further compounding your drop in gas milage.

Yup, ethanol does have the same energy or BTU's (British Thermal Units) that of Gasoline.
(Diesel fuel has more as does jet fuel, just don't use these).
Generally speaking, premium fuel does not have ethanol, but ask the seller or contact the company selling the fuel.
The Tenere (my Tenere, no mods) calls for a minimum of 91 octane, or premium gas.
SHUMBA

 

[SHUMBA]

Most of the people getting 50 mpg are running w/o any panniers or top box, not living in states with 80 mph speed limits and some at higher elevation too. My bike is always loaded up and running panniers, etc. 42 is my average mpg. I haven't really checked lately.

As for winter gas, it's all winter gas now in many places! That was E10 back when we mostly got real gas the rest of the year. Now you have to search and pay more for non-ethanol blended gas. It was a scam then, and still is. You use more to go the same distance, so no pollution benefits, never mind alcohol doesn't store btu's as efficiently as gasoline.

Oh how True!!!
SHUMBA

 

[SHUMBA]

The UK and the US don't use the same octane rating system. What you're buying in the UK as 95 octane fuel would be 91 octane in the states, which on the eastern seaboard is sold as mid-grade. "Premium" grade fuel in the east where I live is 93 octane, which would be equivalent to your grade of 98 octane. Europe uses the RON (Research Octane Number) system, while the US uses the PON system (the Pump Octane Number, which is the average value of the Research Octane Number and the Motor Octane Number).

A gallon of premium (US 93 Octane) is currently about $3.11 a gallon where I live. Regular gas (87 Octane) is about $2.49 a gallon. The price varies quite a bit from state to state (and even county to county) based on transportation distances, taxes, and other factors.

There's a myth that high octane fuel is somehow "better" than lower octane fuel; probably because here in the US they call it "premium". Guys will talk about how they "treated" themselves to a tank of premium. I believed the myth myself at one time in my younger days. Putting high octane gas in an engine that doesn't require it is just a waste of money.

Oh so true...follow the manufacturer's recommended fuel requirements
SHUMBA

 

[Sierra1]

Eric mentioned the speed limit effect on mileage. So true. Was down in south Texas in motorcycle heaven. The roads were tight enough that 40mph was "fast", and chicken strips were non-existent. With the torque of the Tenere, very little throttle input was needed. After hours of joyous roads, it showed that I was getting 52mph. Doesn't get any better than that.

 

[SHUMBA]

Speed is major factor in fuel efficiency or consumption.
I flew for a living and fuel burn at moderate cruise speeds vs the burn at higher speeds resulted in a huge difference.
Drag increases as the square of the airspeed and the power required increases as the cube of the bike's speed.
Something like that.
I flew my bike down I-75 last summer at a great clip tailing a young lady in a pickup truck in a big hurry. We averaged speeds of 95 MPH or about 145 KPH.
I missed a fuel stop near Lansing, but barely made the nest one. I refueled and did a calculation telling me I had only one liter remaining (approx 1/4 gal).. my normal burn is about 5 - 5.2 litres / 100 KM, but on this run at the high speeds it was about 6.2 liters/100 KM.
There's no free lunch eh.?
SHUMBA

 

[SHUMBA]

Oh, I should add to my story about fuel economy, this on my Africa Twin, but it would be applicable to all bikes.
Particularly the Super Tenere with those big fat panniers attached.
SHU