Put some alloys on for winter..

Seat cupra mk 1 alloys which are 16 inch but 7 rather than 6.5 wide.

They are also Et42 instead of standard ET35.

Fitted new rainsport2 205/45/16 w rated tyres on the front too.

They are not rubbing but the car seems to be giving 5-7mpg worse than before, saying that i still need to get the car tracking done.

Any idea of whats going on here?

Edited 4 November, 201015 yr by Static

Offset wont effect it

the wider rims will provide slightly more rolling resistance which might have an effect

also i'm guessing that winter tyres will have a high friction by their very nature so probably need more effort to keep them moving

However i'd guess it's possibly down to tyres that are the wrong size but i just guessing

which wheels are they?

Edited 4 November, 201015 yr by PastyBoy

yeah 245 wide is waaaay off the mark

which wheels are they?

Is it a set of these??

'cos i had an Ibiza before my Fabia and it took 205/45/16 tyres the same as a Fabia VRS

Edited 4 November, 201015 yr by PastyBoy

the tyres are too wide, however, not sure how much of a difference itll make to the mpg tho

Matt

245/50/16 tyres will give a full 10% greater rolling circumference than the standard 205/45/16 (see here). When you're speedo says you're doing 70mph you will actually be doing 77mph, so watch yourself with speed cameras! Similarly, for every mile your odometer reads you will have travelled 1.1miles. I'm suprised you're not having clearance/rubbing problems running that size of tyre.

Thats got to be a typo surely, your never going to get a 245 on a 7 inch rim are you? Thats going to pinch like mad.

Also tried 3 tyre sites, no one even lists a 245/50 16.

Edited 4 November, 201015 yr by Tech1e

Thats got to be a typo surely, your never going to get a 245 on a 7 inch rim are you? Thats going to pinch like mad.

Also tried 3 tyre sites, no one even lists a 245/50 16.

maybe he went to type 215 as 4's right above the 1 if you've got big fingers

corrected, wrong size mentioned! sorry, they are standard tyres 205/45/r16

Edited 4 November, 201015 yr by Static

i only noticed it going from 16's to 18's dropped nearly 10mpg lol

Stick more PSI in.

PSI yea thanks, will try it tomorrow.

mpg could be lower due to the colder weather as the engine will take longer to warm up

possibly

You might want to inflate to the max pressure marked on the sidewall minus about 10 percent.

You might want to inflate to the max pressure marked on the sidewall minus about 10 percent.

dont do that think its around 36psi front 34psi rear

i just used to whack 35psi in all round

Edited 4 November, 201015 yr by BigJase88

New rainsports sap mpg enormously, once the 'newness' has been rubbed off they improve massively - my mpg fell by the same amound last year when I put a new set of rubber on. HTH

Thanks all for the help.

It seems to be PSI as the garage that put the new tyres on had put them at 32 and 31 for front tyres and 27 and 30 for rear!!! Idiots!!

No wonder ive spent all week thinking the alloys i have were a big mistake.

Now set to 36 on front and 34 on rear .. much much better.

Will put up pictures later...

OP, you mentioned that the wheels are wider which suggests they could be heavier, which in turn is likely to adversely affect fuel consumption.