hey guys

just wondering about fuel economy and MPG.

i have gs300 mk2 with standard wheels and stnadard exhaust i was getting about 85-90 miles out of 20 liter petrol. (in town)

since i have changed my exhaust and wheels now i only get about 65 miles out of 20 liter petrol. ( in town )

20 liter petrol and 65 miles in town is that normal average ?

do you think there is some thing wrong with my car ?

cheers

Fuel prices have been going up a lot recently- so 20 litres of fuel will cost more than say a fortnight ago.

What tyre and wheel size did you have / have you got now?

Wheel and tyre size make a difference to what the speedo reads and if the speedo is out, so is your mileometer.

Not much difference but enough to make a difference on £20 worth of fuel. Hope you understand what i mean, the result would be that it wont be as bad mpg as it's showing.



A few things can make a difference though one of has been mentioned (Price)

Does it need a service? (can make a big difference)

Tyre pressures incorrect?

Are you carrying extra weight?

Just a few things that can change your mpg. hope this helps.

Dylan

[quote name='katana92_uk' post='708712' date='Feb 11 2010, 03:22 PM']hey guys

just wondering about fuel economy and MPG.

i have gs300 mk2 with standard wheels and stnadard exhaust i was getting about 85-90 miles out of 20 liter petrol. (in town)

since i have changed my exhaust and wheels now i only get about 65 miles out of 20 liter petrol. ( in town )

20 liter petrol and 65 miles in town is that normal average ?

do you think there is some thing wrong with my car ?

cheers[/quote]

If you are travelling short distances in this cold weather then your fuel consumption figures will look bad. The engine will always use more fuel in cold weather. My 430 is currently giving between 14 and 18 mpg around town. I always brimfill the tank and the OBC figures always match Actual figure when worked out from fuel put in to re-fill tank. How do you know when you have used 20 litres of fuel though? If you are relying on putting 20 litres in when low fuel light comes on then it won't be very accurate, but you appear to be getting around 15mpg which isn't disastrous in a GS in winter.

[quote name='kam05' post='708714' date='Feb 11 2010, 03:29 PM']Fuel prices have been going up a lot recently- so 20 litres of fuel will cost more than say a fortnight ago.[/quote]


true but 20 liter petrol is still 20 liters

[quote name='Dylan69' post='708718' date='Feb 11 2010, 03:48 PM']What tyre and wheel size did you have / have you got now?


Does it need a service? (can make a big difference)



Dylan[/quote]

some good points there. i was running 17" wheels with 225 50 17 and now i am running 18" with 225 40 18.

i think car does need service. but it drives ok no problems or any hesitation with pulling or revs.

thanks for inputs guys..

well i did give my car good check today and i think there are few things which are / were causing problem.

1. i noticed front both brakes were binding
2. air filter was filthy as hell. dead flies, fluff, grass etc and i even found 2 dead snails
3. my car battery totally died few weeks ago so i believe by changing battery i have done some sort of ECU reset and while ecu is learning car is consuming more fuel.
4. my mechanic told me in cold winters car consumes more fuel coz engine struggles to warm up ?

my findings so far....any more suggestions please keep them coming

thanks guys

If my calculations are right your new tyres are 20mm smaller in diameter than the old ones and really the reading should have gone the other way slightly (as in showing more mpg) unless my brain is not engaged properly at the moment. I think though you'll find the binding brakes combined with dirty filter will have been your problem.

[quote name='Dylan69' post='708940' date='Feb 13 2010, 10:02 AM']If my calculations are right your new tyres are 20mm smaller in diameter than the old ones and really the reading should have gone the other way slightly (as in showing more mpg) unless my brain is not engaged properly at the moment. I think though you'll find the binding brakes combined with dirty filter will have been your problem.[/quote]

I make it 15mm larger diameter.

[quote name='dave1' post='708960' date='Feb 13 2010, 02:33 PM'][quote name='Dylan69' post='708940' date='Feb 13 2010, 10:02 AM']If my calculations are right your new tyres are 20mm smaller in diameter than the old ones and really the reading should have gone the other way slightly (as in showing more mpg) unless my brain is not engaged properly at the moment. I think though you'll find the binding brakes combined with dirty filter will have been your problem.[/quote]

I make it 15mm larger diameter.
[/quote]


Just double checked
[img]http://i144.photobucket.com/albums/r176/DYL4N69/tyrecalculator.jpg[/img]

so my car is showing more MPG than it should...?

It'd only be about 3 miles in every hundred not worth worrying about.

[quote name='Dylan69' post='708962' date='Feb 13 2010, 03:08 PM'][quote name='dave1' post='708960' date='Feb 13 2010, 02:33 PM'][quote name='Dylan69' post='708940' date='Feb 13 2010, 10:02 AM']If my calculations are right your new tyres are 20mm smaller in diameter than the old ones and really the reading should have gone the other way slightly (as in showing more mpg) unless my brain is not engaged properly at the moment. I think though you'll find the binding brakes combined with dirty filter will have been your problem.[/quote]

I make it 15mm larger diameter.
[/quote]


Just double checked
[img]http://i144.photobucket.com/albums/r176/DYL4N69/tyrecalculator.jpg[/img]
[/quote]
[b]Apologies.......I stand corrected.[/b]

No problem