Hi all

 

Do the roll resistance ratings that tyres get really make that much difference to mpg on a day to day basis? I'm debating a winter tyre set and am considering paying more to 'achieve' a rating of C, as opposed to the E that a lot get.

 

I am slightly obsessed with achieving a decent mpg as I HATE spending money on diesel!

 

Cheers in advance for the opinions. 

 

Si

Unfortunately the winter tyres get tested with reference to summer conditions so will always show worse and have no real comparison whatsoever!

How much difference is there in a cat C tyre versus say a cat E tyre?

They rekon 7% from the best to the worst

If it helps (and I doubt it!) I put on some Dunlop Wintersport 4Ds on in place of the OEM Sport SP01s summers and the mpg is a noticeable bit better in dry conditions - about 3-5%. Don't know the ratings for either however.

Can't  talk about winters I'm afraid but I changed my fronts only from a G (Maxxis MAV1) to an A (Goodyear Efficient Grip performance) and my mpg jumped up by about 10%.

Edited 7 January, 201412 yr by Aspman

My winters are E and my summers (Michelin energy) are B.

Difference is marginal around 2% in my experiences. More fuel is used in the colder weather anyway. I run the same size on both 205 55 16

The winters are cheaper than the summers so its cost netural to me.

I assume that you check your pressures regularly and adjust for temperature variations?

 

You use more screenwash in winter too...

since moving from summers to winters (18s to 16s) my mpg has actually improved very slightly. maybe because the wheels/tyres are now lighter.

The claimed difference between C and E rating is 0.14 L/100 km (see e.g. http://tyrelabel.bridgestone.eu/psr/en), so you can do the sums based on a guess at the tyre life. But how accurate it is anyone's guess. The trouble is that the differences are so small that it's pretty much impossible to tell for sure based on your own driving (due to too many other variables). Note there is no category D by the way, so the difference between C and E isn't as big as it seems.

Edited 7 January, 201412 yr by Ultrasonic