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Model specific boards => Golf mk4 => Topic started by: arnoldlog1 on 07 September 2006, 19:10

Title: fuel consumption??
Post by: arnoldlog1 on 07 September 2006, 19:10
I've just fitted some new style r32 alloys to my gt tdi 130, but my fuel consumption has dropped by at least 10 mpg(sometimes 15). any ideas why?? I bought the wheels from wheelbase and fitted them myself is it because they need tracking?? the wheels are slightly wider does that make a difference?

any help greatly received

ps they look cool tho  :cool:
Title: Re: fuel consumption??
Post by: Rhyso on 07 September 2006, 20:38
think about it;

you've fitted LARGER wheels. therefore you have more rolling resistance and therefore you need more energy to move  :nerd:

get some pics up then  :wink:
Title: Re: fuel consumption??
Post by: arnoldlog1 on 07 September 2006, 21:06
yeah OK i get Ur point  :wink:

I'll take some pics at the weekend whens its clean and get them posted
Title: Re: fuel consumption??
Post by: Stu-1.8T on 07 September 2006, 23:37
I wouldn't of thought changing the wheels would make you lose 10-15 mpg. Could it be that the computer is not calibrated for the larger wheels or something?? 
Title: Re: fuel consumption??
Post by: Rhyso on 08 September 2006, 12:50
bigger wheels also  = more weight!

replica wheels are notorious for being very heavy (only assuming the orginal poster has replicas) but even geniune R32 alloys will be heavier than the standard alloys

bigger wheels + more weight = more fuel consumption.

Title: Re: fuel consumption??
Post by: arnoldlog1 on 08 September 2006, 16:54
maybe not 15 but definetly 8 to 10 ish mpg loss, i'm not 2 upset about, because i don't do loads of miles, and they do look good.  :cool:

just need to get it lower now, and remap it then i'll be happy!!!


pics coming soon  :wink:
Title: Re: fuel consumption??
Post by: GazB on 08 September 2006, 18:33
I would not of thought 8 - 10, I got genuine R32 wheels on mine and it still reads 50mpg+ on a run
Title: Re: fuel consumption??
Post by: charri42 on 08 September 2006, 19:34
bear in mind if the rolling circumference is bigger (which it will be on 18's) you are travelling further than your car thinks! - hence mpg perhaps better than reading.
Title: Re: fuel consumption??
Post by: Stu-1.8T on 08 September 2006, 21:43
bear in mind if the rolling circumference is bigger (which it will be on 18's) you are travelling further than your car thinks! - hence mpg perhaps better than reading.

Yes, that's what I meant, but you have wrote it betta aint ya. :embarassed:
Title: Re: fuel consumption??
Post by: Flipmode on 09 September 2006, 18:20
u shouldn't be losing that much mpg, i went from 16" to 18" and lost about 2mpg at most, get the tracking done anyway.
Title: Re: fuel consumption??
Post by: Mantamad on 09 September 2006, 21:32
Do you have to fit a lower profile tyre than standard when you increase wheel diameter so that the overall diameter of the wheel and tyre combined does not increase, for instance if you had standard 15" wheels with 60 profile tyres, you would change to 16" but fit 55 profile, or 17" and 45 profile, not to certain of the ins and outs of this but it does ring a bell.
Title: Re: fuel consumption??
Post by: Flipmode on 10 September 2006, 11:42
yes mate u do