[Frosticles]

Have recently fitted a set of 18" RS4's and have noticed that my fuel economy has gone way down. Before, I was running 16" BBS RX11's and was averaging late 50's early 60's. Now with the 18's I'm struggling in the mid 40's!!!!! Anyone else experienced this?? Thanx in advance, Kev.

 

[Royster]

I found it the otherway round if you get my drift..

My anni was having wheels replaced so I fitted some 4mo alloys (16") and my mpg climbed a bit..

18s=36-39MPG

16s=38-46MPG

 

[Sem]

I still get about 52mpg on my daily commute into work, I have 8.5x18" BBS CH.

Used to get about 56/57mpg on my old 16's though.

 

[dc]

I'm averaging 40-42 mpg m8, welcome to the club[8D]

 

[carl310166]

I lost about 4-5 mpg on my Audi A3 1.8 turbo quattro,when i replaced the 16" with OEM RSTT 18"s,it ended up doing 25mpg !

Sold that to buy my 130pd.

I did notice that my 50-70 in top changed dramtically,from about 7.5 secs,to about 11 sec,i was told this was down to fitting the 18s,i can't see it myself,but there again,i can't understand why the mpg is down,because the rolling circumference is supposed to be very close?

Anybody done in gear accelleration comparissons since fitting bigger wheels?

 

[Bikealarmblair]

I've just had 18"s fitted to my 150pd with original 16" wheels I used to get 45ish & now its just under 40...

Not sure if it the extra width/weight of the wheel or if the vagcom needs to be told the wheel size has changed....

 

[scarum]

Turning circumference should not have changed unless you bought the wrong rim size and tyres to match.

Are you sure you are not just driving that little harder, what with larger rims it's all adds to that firmer ride.

 

[UK Paul]

15 to 17" got a measured 4-5 mpg fall in mpg.

 

[4pot]

I dream of such economic returns [:O]

[]

 

[Milkfloat]

Same as UK-Paul, however it could be that I went from semi slick (read bald)to very grippy tyres (read new). Would be interesting to test on 2 sets of wheels with brand new tyres of the same brand/model.

 

[andymac]

I struggle to get 24, stop whinging.......

 

[hornetrider]

same here I'm afraid. changed to 18s about 2000 miles ago

used to be 54-56mpg, now I'm lucky to hit 52, usually about 48 or 49.

still, oggling my RS6's is well worth it!

 

[tylerama]

So, you do actually lose a bit in MPG then ? This is startin' to put me off my RS4's i'm about to buy :-(

 

[carl310166]

So nobody is interested if acceleration is lost as well ???

 

[BORA_TOM]

I lost 4-5 mpg as well but put this down to being a penny pincher and opting for Nankang tyres rather than proper ones !

 

[x1-immy]

Bigger tyre = more tyre contact = more road resistence = more effort needed to turn the tyre = worse fuel economy.

 

[GaryM]

Quote: posted by carl310166 on 29/09/2004 05:40:57

I did notice that my 50-70 in top changed dramtically,from about 7.5 secs,to about 11 sec,i was told this was down to fitting the 18s

Really, has this affected anybody else?

 

[talk-torque]

I noticed a 2-3mpg drop going from worn Bridgestones to new Goodyear GSD3's, both on 16" Montreals, so the tyre type could be a big factor.

 

[Frosticles]

As far as accelleration goes, Did the 1/4 mile at Santa Pod for the GTI Festival and got a best of 14.980 on 16's. Went to the GTI crap day at York Last month and could only get a best of 15.300. Still not bad but wasn't too happy. What do the Anni boys/Girls get with their standard 18" wheels economy wise??? I did though, notice a very large gain in weight with the RS4's compared to the RX11's. This could have something to do with it initially but wouldn't have thought that it would have affected it once rolling as the resistance shouldn't really come into it?? Using Avon tyres by the way which is quite a reputable brand I think.

 

[AshR32]

Maybe it has something to do with the fact that the actual rim part of a wheel is the heaviest bit?. Therefore even with the same overall diameter and circumference, there is more weight further from the centre, hence more force required to accelerate the rotational speed of the wheel??

Just a thought....

By the way, I know someone who put RS4's on an A4 tdi and he said the performance was ruined!....[:O]

Ash.