Gas Mileage Conundrum

I'm been looking at the various MPG obtained by you guys and I'm at a loss to make the figures compute. There are a lot of USA riders who get 50+mpg . There are 1.2 Imperial gallons to a US gallon so you're getting the equivalent to 60mpg Imperial. Now I have not checked for a long time but around town I was getting about 35mpg Imp. On a 2000 mile trip around France last year, I got about 45mpg Imp. I've never heard of anyone in UK getting anything like 60mpg. Soooooo, my question is Why is there such a big difference?

Bewildered from UK

Ian

How old is your Silverwing, Ian?
There is a feeling that something's been done to later models which has improved economy.
On my latest trip to France a couple of weeks ago I averaged 55.1 MPG (imperial), based on my figures written down as I filled up but not taking into account variations on brimming the tank.
The trip included dawdling along country lanes and quite a bit of motorway thrashing 8-900 miles in all.

Hi Mike
She's a 2001, non ABS. Only had 1700 miles on her (genuine) when I got her 18 months ago. I can't get my signature to show for some reason?
I need to fill up tomorrow, so I'll make a note and see what mpg figure I get.
I am very heavy handed and most of my riding is just to the shops, so I wouldn't expect miracles anyway, but I thought I'd get better on a long run. Even my Buell gets 48mpg on a decent run and my Goldwing got about 42mpg (1800)

hahahahhahah I open my mouth and put my foot straight in!!!!! My signature does indeed work, now...........

Mm. I suspect age is the main problem.
I wonder what the cut-off date is.

You may well be right Mike, I'll keep a check on my MPG over then next few weeks and see how I get on. I suspect the HiT clutch and sliders (when they arrive) may not help the situation

goldwinger wrote:

I am very heavy handed and most of my riding is just to the shops, so I wouldn't expect miracles anyway,

I believe you just solved your problem.

bigbird wrote:

I believe you just solved your problem.

Thanks BB, I presume you mean go to shops further away?

goldwinger wrote:

bigbird wrote:

I believe you just solved your problem.

Thanks BB, I presume you mean go to shops further away?

No, nothing to do with shopping.

Hmmmmmm OK, you have me stumped..........Surely you don't mean use less throttle? I mean, thats WHY it's called a throttle......lol

This may have little or nothing to do with your problem, but I started noticing my MPG dropping slightly. It seemed like every fill up I was going down about 1 or 2 MPG from last time. When I first got the bike I could get 60MPG with pure gas and 54-55MPG with ethanol. Lately it's been at about 47-49MPG. I have just under 7000 miles on the bike and I had never messed with the air filter so I thought I'd take it out and look at it. That thing was cram packed full of dirt and dust! This surprised me as I only drive it on pavement and very rarely go anywhere that even has a gravel parking lot. I just took and knocked as much of it out as I could and put it back in. The next day I took a ride and was getting 55MPG again just like the day I bought the thing brand new. I ordered myself a new filter and it came in yesterday but I have yet to install it. They're NOT cheap.

I'm not saying that's your problem, but it's a good place to look.

smorkle wrote:

I ordered myself a new filter and it came in yesterday but I have yet to install it. They're NOT cheap.

Have you considered a re-useable K & N?

Thanks smorkle, but I've just fitted a K & N last week but not had a chance to check MPG. The old filter was pretty filthy though, so you may well be right. I need to fill up tomorrow as the warning came on today after 112 miles.

now since we're talking about air filters... Anyone used Hiflofiltro Air Filter before?

Ian,

The SWing will use a lot of gas if you use the throttle hard. I know for times I was always going fast and racing a lot I would get high 30's or 40 mpg at most. But then I was having a lot of fun too. You may also want to check the air mixture screws to make sure your air/fuel mixture is correct. I need to take mine in to have them adjusted since I mistakenly turned 1 of them a few turns.

I don't know how to do this but maybe someone on the site does. If you have the piece of equipment to do it , it doesn't sound too difficult. But you may want to try that first and also maybe run 1 tank o fgas where you ride conservatively just to see what kind of mileage you get when riding "like an old man". lol

Ok, I filled up this morning and I'm getting 45.17 MPG. On reflection, in the last week I've changed the engine and final drive oil, changed a tall Givi screen for the airflow, changed to Iridium plugs and replaced the OEM air filter with a K & N. These were done with the tank on about 1/2, so I should see even better figures on my next fill-up.

Ian

JeffR_ wrote:

You may also want to check the air mixture screws to make sure your air/fuel mixture is correct. I need to take mine in to have them adjusted since I mistakenly turned 1 of them a few turns.
I don't know how to do this but maybe someone on the site does. If you have the piece of equipment to do it , it doesn't sound too difficult. But you may want to try that first and also maybe run 1 tank o fgas where you ride conservatively just to see what kind of mileage you get when riding "like an old man". lol

I believe Jeff is referring to the throttle balancing, not air/fuel mixture. The air/fuel mixture is predetermined by the ECU, relying on inputs from the throttle position sensor, temp sensor, O2 sensor ('07 and later models), and even more sensors. This is not adjustable unless you override it with a Power Commander. The screws are for balancing the throttle plates. Each cylinder has its own throttle plate which controls the amount of air entering each intake port. If the air flow is not balanced, the cylinders will run unevenly, resulting in surging, fluctuating idle speed, excessive fuel consumption, reduced power, etc.
You need a vacuum gauge, preferably dual unit, so that the vacuum can be observed concurrently in both cylinders. By adjusting the individual throttle plates, you can balance the vacuum so that both cylinders are sucking equal volumes of air. Then the ECU will provide exact amounts of fuel for both cylinders.
Hope this helps.

The air filter can change rather rapidly from looking clean to dirty.

I looked at mine at 12,000 miles and thought it looked brand new, so I left it in place. Just did the 16,000 mile service and it looked filthy - rather oily and black looking. I got the scoot used (with 3800 miles on it) and am certain that it had at least 8200 miles on the filter when I checked at 12k. The quick change from clean to dirty at 16k surprised me.

However, my mpg had not dropped much, if at all. I tend to run it hard, and get 44-48 during the cold months (fewer long trips, and more warm up time) and 48-52 during the warmer months. I record every fill up and find 48-50 constantly.

I used to turn wrenches on airplanes quite some time back so while I may have the necessary skills to maintain my bike's engine, I'd rather pay someone else to turn wrenches nowadays. :-)

I've found a highly reputable shop in my area that has done my tune-ups for me and knows what to look for (it's both a Honda and Yamaha shop but they work on just about everything). Since I ride pretty much year-round, I usually get my spring tune up in February or March and keep getting tuned up the rest of the season about every three to four months. My spring tune up wasn't cheap this year - had to replace several things including my drive belt (was below the service limit), rear brake, front tire, clutch (too much chatter on it for my comfort), battery, and all the usual stuff. That was an expensive tune-up but I knew that I'd still make back the cost in savings riding in less than one season over driving a cage. Of course, it goes without saying, I'd rather be riding than driving anyway. :-)

I combine that with a fuel additive that attempts to eliminate the effects of ethanol and I come up with 51-52mpg when I'm not trying to save gas and better when I am. I've gotten as high as 62mpg (US) on a single tank on my 2003 SWing. In that case, I was riding back-roads mostly on a longer trip keeping my average speed around 45mph.