2008 Fuel Economy Function Malfunction?

[cmc1978]

While riding my new 08 Speed Triple, I noticed the instantaneous and average fuel economy numbers in teh instrument cluster are much too high. Speedometer and odometer seem right. But my bike tells me I am getting ~60-70 miles/USgallon while holding speed at 65 miles/hour. Filling the tank to full and then at the next fill up, comparing miles travelled to the gas I have to put back to fill it to the top reveals numbers more in the mid 30 miles/USgallon to start. I assume this is due to break in. The last tank or two were more low to mid 40s. I searched, and 40s agrees with what most of you are getting on your 05+ Speed Triples.

So did/does anyone else have a highly optimistic fuel economy gauge? How did the dealer fix it? Mine is an 08 Speed Triple with the dual arrow slip on cans (w/o DB killer insert) and the apprpriate Triumph ECU map. I wish it got 60+ mpg, but I know that is not right. I want the device to be accurate. I never had an issue with this function on a Daytona 675... Could this be from the dealer making a mistake when loading the new ECU map for the arrow slip on exhaust? Could they have unplugged the O2 sensor for the exhaust which causes this malfunction? (I think it is near the heat shield under the right foot peg?)

I searched "fuel economy" and did not see anyone else making this complaint.

[Bohdan]

Check if your bike is set for US or UK gallons. With power on, but engine not runing press and hold all 3 buttons until speedo shows number 1-3. It should be "3" for US, "2" means UK. If it is "2", then press scroll button to change it.

On a side note: It would be so much easier if people would indicate their location in the signon (US,UK, Europe, Antarctica...)

[cmc1978]

Thanks Bohdan, I will try that tonight. Sorry for any confusion, I am in the US. I updated my profile accordingly

[cmc1978]

I tired the fix yesterday and it did not seem to help. I could not remember whether 2 or 3 meant US. And I found for sure 1 is all metric. So I set it to 2 and then 3 and simply rode to see which one got realistic numbers. I think it started on 2. So I set it to 3. I rode and the fuel econ numbers seemed to go up even higher! So I set it to 2, and the numbers were still high, but at least lower than 3. Does something else need to be reset? Again, speedometer and odometer seem a-ok

[S3Junkie]

Dude it's just a cheesy computer algorithm to "ESTIMATE" what the bike is getting, most likely based on speed/RPM, wheel rotations, etc. It has no way to take into consideration the wind factor, aerodynamics (clothing for example), weight of the rider, etc. It's just a cheesy gimmick to add to the list of useless features to help sell the bike and justify the money spent.

At best, just watch it over time to get an idea of what riding conditions (speed, rpms, shifting pattern,etc) are yielding the best mpg for you and maybe try to stay within that range as much as you can to maximize your fuel economy.

However, you don't purchase an S3 with fuel economy in mind. Buy a little commuter for the gas mileage and save the S3 for the weekend blast offs.

[cmc1978]

I had the same feature on a Daytona 675, and it worked just fine. It was very close to the old method of fill it full, run it , track miles, fill it full again and then calculate. No reason why it should not work here.

Have you ever worked in engineering? I assure you it is not a cheesy algorithm. Someone probably spent good time trying to get that as accurate as possbile. It can account for rider size, wind load, grade, etc by monitoring fuel flow into the engine. When there is more wind, fuel used goes up. When a 130lb or 220lb individual gets on, it can account for that by more fuel into the engine. To be more accurate, it could also use air volume into the engine to estimate the fuel used from the fueling map and thus estimate economy.

I am not concerned with the number per se. If that was my concern, I would buy a Ninja 250. But I would like every feature of the bike to work. There is no reason for it to not work, especially with historical precedent on other bikes of such a feature being fairly accurate. Its also been a fairly accurate feature on cars for many years. Why excuse Triumph from making the best products we know they can?

[S3Junkie]

As usual I'm so glad I bother to chime in here. lol

[LarryS]

And here I thought MPG was a clever ploy to help convince my wife that a 135bph motorcycle was all about saving money!

[cmc1978]

I did not mean to imply that I do not appreciate your opinion. I do appreciate your time to reply. But I think your comment made light of someone’s hard work. And I felt obliged to defend that nameless engineer. I am sure the feature is more complicated than you or I assume.

For example, my Uncle is a controls engineer at an auto company. He told me one of his first tasks at the company was to develop the algorithm to discern exterior air temperature. Easy you say? They did not want to pay for a separate sensor just for that function. So he had to develop a control scheme to predict air temperature based on the sensors he did have. Intake air temperature, coolant temperature, mass air flow volume, vehicle speed, etc. All that effort and testing just to tell you its around 72 deg F outside and save money on one cheap sensor.

If you put your bike on a dyno, and it made 15 HP less than everyone elses average power output, would you not complain? Manufacturing variation is understandable. And I do not expect this thing to be accurate to within 0.25 mpg. But when a feature is much less than what was promised (bike is not getting 60-70 mpg), would you not make a comment and try to understand the issue? At this point its all of useless. A malfunction is a malfunction. Would you excuse your odometer being 10% off, causing your bike to register mileage much faster than it actually is? You could just compensate in your head?

Why would you regret replying? This is simply friendly, intelligent conversation with some substance as opposed to the usual 1-2 liners. Is that not appreciated here

[Joemomma]

Well, mine reads in the 60 MPG ( US gallons ) range when cruising at steady state 65mph, but dips down to like 20 MPG when I ride it like I bought it to ride. Average is somewhere in the 40's, exactly what I would expect. I think it functions a tad optimistically, but pretty well all in all.

BTW, I have discovered with my van ( Ford E-350 Xtended loaded to the limit ) that by slowing my average speed from 85mph to 72mph on the highway I can pick up 3-4MPG. 10 MPG to 14 is a HUGE difference. I suspect if one were to drone along on the highway at a steady 65mph, never having a moments fun, that 50MPG might be realistic.