Wide wheels decreases MPG significantly?
03-31-09, 06:50 PM
#16
As I read this a thought occurred to me about checking your gas mileage. I've not tried this yet but it might be interesting to test out.
My portable Garmin Nav has a built in trip computer, and I find it very accurate for MPH and Miles driven. If you had one, or could borrow one, for a tank full you could find out how many miles you've driven and manually calculate your MPG at your next fill up.
Might also be interesting to see the difference in miles from the GPS to your ODO.
Just a thought.
My portable Garmin Nav has a built in trip computer, and I find it very accurate for MPH and Miles driven. If you had one, or could borrow one, for a tank full you could find out how many miles you've driven and manually calculate your MPG at your next fill up.
Might also be interesting to see the difference in miles from the GPS to your ODO.
Just a thought.
03-31-09, 08:42 PM
#18
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04-01-09, 03:48 AM
#23
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i've seen my mileage go down also. with the larger wheels there will be a larger rolling resistance. check your pressures that can also have an effect on mileage.
it is fine to stagger an awd car as long as the front and rears have the same rolling diameter. i am running the same size tires and the front to rear rolling diameter at .01% difference. with upgrading rims the overall diameter from the stocks of course will increase slightly. since this is the case i have noticed my revs drop on the highway about 300rpms. the car knows it's traveling at xx speed and knows what the fuel flow rate is.
i guess the lower mpg is all about looking ballin' haha.
i'm just gonna live with it, i'm averaging 20mpg mixed 50/50 where before i was at maybe 23mpg. and that's at about 80mph on the highway.
it is fine to stagger an awd car as long as the front and rears have the same rolling diameter. i am running the same size tires and the front to rear rolling diameter at .01% difference. with upgrading rims the overall diameter from the stocks of course will increase slightly. since this is the case i have noticed my revs drop on the highway about 300rpms. the car knows it's traveling at xx speed and knows what the fuel flow rate is.
i guess the lower mpg is all about looking ballin' haha.
i'm just gonna live with it, i'm averaging 20mpg mixed 50/50 where before i was at maybe 23mpg. and that's at about 80mph on the highway.
04-01-09, 03:46 PM
#25
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Finally went staggered on my AWD today. Plain OEM R18 rims from IS250 Sport and Michelin Pilot sport sp2 tires 225/40 front and 255/35 rear. Drives really nice.
There shouldn't be any troubles if you keep the wheels diameter close to equal. For example BWM 325xi (AWD) goes with 225/40/18 front and 255/35/18 rear in stock. Default torque dispension for Lexus is 30 front 70 rear, for BWM 37 front and 63 rear. So I think we should be fine with our AWD staggered properly
There shouldn't be any troubles if you keep the wheels diameter close to equal. For example BWM 325xi (AWD) goes with 225/40/18 front and 255/35/18 rear in stock. Default torque dispension for Lexus is 30 front 70 rear, for BWM 37 front and 63 rear. So I think we should be fine with our AWD staggered properly
04-01-09, 04:31 PM
#27
Thats weird. i'm on 19's and i run 225 fronts and 265 rears and my mpg is just fine. Its like i'm on stock. But the most important thing to me, is checking the tire pressure. I'm always at 40psi, and i check it weekly. Remember if you have a three piece wheel it will always leak somehow if you let it sit too long. But anyways, i think if you drive a luxury car (Lexus) you shouldnt be complaining about gas. but thats just me
04-01-09, 05:53 PM
#28
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Originally Posted by Phil888
Thats weird. i'm on 19's and i run 225 fronts and 265 rears and my mpg is just fine. Its like i'm on stock. But the most important thing to me, is checking the tire pressure. I'm always at 40psi, and i check it weekly. Remember if you have a three piece wheel it will always leak somehow if you let it sit too long. But anyways, i think if you drive a luxury car (Lexus) you shouldnt be complaining about gas. but thats just me
If you want to talk about the "programmed" bias then you should think about the % error the bias will have to over look due to tire pressure difference front and rear causing different rolling diameter, tire wear front and rear causing different rolling resistance front and rear, front and rear load to cause different "deflation" in the front and rear tires, all of those are no difference than the .7" inch in rolling diameter difference on my setup, its all within a given threshold.
Last edited by mikez; 04-01-09 at 05:56 PM.
04-03-09, 07:12 AM
#30
I am not sure if its the way I've been driving (which havent changed much cept once or twice I push it a little to explore some new found grip), my avg fuel consumption per tank went from 29 ish to 24 ish on a local/highway mix.
My consumption for mostly highway went from 31 ish to a nice 25 mpg.
My tires were 225 all around and now its 235 front and 275 rears.
Dang if I gotta fill up weekly I might have to retire this from its daily obligations
My consumption for mostly highway went from 31 ish to a nice 25 mpg.
My tires were 225 all around and now its 235 front and 275 rears.
Dang if I gotta fill up weekly I might have to retire this from its daily obligations