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Decline in MPG ??

Posted: Thu Feb 02, 2012 10:19 am
by Scottish
Hey folks, usually after i fill up and reset the trip i would get up to 49miles before the first bar of the fuel gauge went down....the last few times its started going down at about 34 :(

Any ideas as to what might be causing this decrease ?

Re: Decline in MPG ??

Posted: Thu Feb 02, 2012 11:14 am
by gn2
Number of factors, belt wear, cold weather, sticky brakes, you've been at the pies during Xmas, that kind of thing.

Re: Decline in MPG ??

Posted: Thu Feb 02, 2012 12:24 pm
by Fiah
Cold weather definitely has an effect on the mileage I'm getting.

Re: Decline in MPG ??

Posted: Thu Feb 02, 2012 1:30 pm
by Woolley
ive always noticed a pretty major drop in mpg in the car during winter compared to summer. Its most likely that.

Re: Decline in MPG ??

Posted: Thu Feb 02, 2012 1:31 pm
by Esdain
ye, i agree with the cold. it's a noticeable drop but i think it will climb come the warmer months, also i would check to make sure your air filter isn;t too dirty. clogged filter = machine has to work harder

Re: Decline in MPG ??

Posted: Thu Feb 02, 2012 1:50 pm
by Scottish
Cheers, dont feel so bad about it now, better check that air filter tho. :)

Re: Decline in MPG ??

Posted: Thu Feb 02, 2012 6:01 pm
by Fiah
You could change the oil to something thinner as well. The dealer put 10W40 in mine last november, and with -10C my PCX really hates them now. I'd change it to 0W30 but after riding my PCX through this weather I'd rather spend my evening on the couch :P

Re: Decline in MPG ??

Posted: Fri Feb 03, 2012 9:47 am
by Scottish
Fiah wrote: riding my PCX through this weather I'd rather spend my evening on the couch :P
Agreed !! :D

Re: Decline in MPG ??

Posted: Fri Feb 03, 2012 10:38 am
by gn2
It was -6.5°C this morning on my 27 mile commute to work and a positively toasty warm 2.3°C on the way home.

Re: Decline in MPG ??

Posted: Fri Feb 03, 2012 11:48 am
by maddiedog
Damn, GN2, you're insane. That's REALLY cold.

I won't go out unless it's over 40F / 4.5C in the morning. Even then, it's usually up to 60F / 15.6C by the afternoon. I freeze in that kind of cold, I can't imagine -6.5. I guess I'm not built like a Scotsman though. :P

Re: Decline in MPG ??

Posted: Fri Feb 03, 2012 1:07 pm
by Cookie
Well done GN2 - respect to that man.
Regarding the fuel consumption problem, I think the cold weather does affect it a bit as people have said.
Do check the air filter though.
I too have had a slight drop in economy. I put a new air filter in the other day, after 9,000 miles the old one was pretty mucky.
It might be my imagination but the bike does seem a bit more sprightly now.
Cookie

Re: Decline in MPG ??

Posted: Fri Feb 03, 2012 2:06 pm
by Scottish
pfffffffffft @ Gn2's journey, I went from Glasgow via Glencoe up Lochness to Inverness and across the Moray firth in December for Xmas....dunno what the temp was but it was no picinc let me tell you!!

Re: Decline in MPG ??

Posted: Fri Feb 03, 2012 5:41 pm
by edscoot
maddiedog wrote: I won't go out unless it's over 40F / 4.5C in the morning. Even then, it's usually up to 60F / 15.6C by the afternoon.
15.6C is summer daytime temps in the north of England.

OP: I haven't been keeping track of my own mpg recently, but it will go down in the cold. My car will do 26-27mpg commuting in the summer but only 19-21mpg in the coldest weather (0 to -10 or colder).

Re: Decline in MPG ??

Posted: Sat Feb 04, 2012 11:10 pm
by ese12105
I've been having the same problem. In the summer I was going 40 to 50 miles before the first bar would disappear. Then it started getting cold and now it's between 25 to 29. My mileage went from low to mid 90's down to mid 70's. Feel free to look at my fuelly. It's got every fill up I've ever done. I did change the spark plug and oil on my last tank since I've almost hit 5000 miles and I think the spark plug has helped a little. I'm looking forward to the warmer weather so I can lose some gear and see some better mileage. Not looking forward to 110+ F though... Oh well.

Re: Decline in MPG ??

Posted: Mon Feb 06, 2012 6:54 pm
by al69
Mine has dropped with the cooler weather too.Coldest ive been out is -3 boy do i appreciate those tucano urbano handlebar muffs when its that cold !! That was working lates a couple of weeks ago, the wind chill is the real killer as its probably a lot less than -3 when you get some speed up.
Tbh ive only really felt it when changing into my gear thats been stored on the scooter all day and really pre-chilled.Its plain horrible but thats how it is so i have to get on with it and get into as quick as i can.Once im in it a little bit of moving around and my bodyheat takes the chill out of it all.

With the really cold weather ive noticed the throttle response is sharper which is to be expected really as you are squeezing more air in as its so cold and denser, hence the drop in fuel economy.

Re: Decline in MPG ??

Posted: Tue Feb 07, 2012 1:25 am
by gn2
Maybe the auto choke (or fuel injection equivalent) is on for longer in the cold...?

Re: Decline in MPG ??

Posted: Wed Feb 08, 2012 1:26 am
by Taz

Re: Decline in MPG ??

Posted: Wed Feb 08, 2012 1:45 am
by ese12105
Vary interesting. Thanks for the link!