Tyres and fuel consumption

[jphealy]

I recently got four new tyres put on my car.  The old ones were Dunlop SP SPORT 9090.  The rear ones weren't too badly worn, but the front were pretty low on tread depth.  In any case, I decided I'd start fresh with a full new set of Goodyear Eagle F1 Asymmetrics.

Since I replaced them, I have been delighted with the grip levels, but my fuel consumption has taken a bit of a hit.  I used to get about 30mpg on my commute to work.  Now I'm getting about 26-27mpg.

Have other people experienced this?  Is it more to do with the type of tyre, or could it be that more heavily worn tyres can get better mpg?

The tyre fitter also told me that the driver's side CV boot is split and should be replaced.  I haven't got around to getting this done yet, but is it possible that that could be hurting my mpg?

[bacillus]

What tyre pressure are you using?

[jphealy]

About 2.4bar all-round.  The same as with the old tyres.

[mac7]

I've experienced changes in fuel consumption when changing tyre manufacturer. There can be significant differences in tread width, contact patch and tread compound between different makes of tyre which can all affect mpg.

I wouldn't think the CV boot would make any difference to fuel consumption unless all the grease has been washed out - but then the CV would have failed. If you're doing lots of motorway driving I'd get it fixed sooner rather than later though.

[tuscan_thunder]

My consumption is, if anything, slightly improved with 2 Eagle F1s on the front in place of SP9000s.  (Which were terrible tyres)

[DJGTi]

My mpg dropped by a couple when I replaced my worn out Bridgestones with GoodYear F1s.

I assume more grip=more drag (very simply!)

[FamilyDub]

I assume more grip=more drag

^^^ Yep.

[jphealy]

I guess that makes sense - there's DEFINITELY more grip!!