Yes, i know, before you say it, you have assumed that i have 16" 205 wheels and tyres fitted, giving lighter weight and less rolling-resistance and a difference in rolling-radius...

BUT, my winter wheels are 18" Luxon alloy's with 225 verdestine WintracXtreme's fitted.

I appear to be achieving 4 or more, more MPG with the winter's on, compared to Thermisto Wheels and Toyo C1s tyres during the summer months.

I would have thought that the additional groves in the winter tyres, and silica tread-compound, would have only increased the fuel consumption, not decreased?

This is the 3rd winter i've had the same wheels on, but changed from Continental tyres in May, so have never gone from Toyo's to Winter's before now.

Has anyone else found this....?

Al.

My economy has gone worse with winter tyres. Same size as the summertyres (205/55-16). Car has gone from 22 km/l to 20 km/l.

I'm now on 16" (205/55) winter set, swapping from 18" (225/40) and can't see any difference in fuel economy.

I've gone from 18" with conti summer tyres to 16" with conti winters ( the latest TS850's) and have noticed an increase of 4-5mpg, quite amazing! I put it down to latest tyre technological developments creating lower rolling resistance, maybe carcass construction amongst other things!

Incidentally I ran for a day with the previous version TS830's because the tyre fitters messed up fitting a tyre I hadn't asked for I managed about 200 miles on those before the mistake was corrected and I noticed no change to mpg with TS830 tyres.

Mine always goes up each year I change them over 225/40/18’s to 205/55/16 winters.

My fuel consumption on 205/55/16 winters improved by almost 10% over the standard 225/40/18s. Everything else, ride, handling, wear, comfort and noise improved too. I intend to stick with the 16" wheels for summer now with appropriate tyres. Any reason why not, other than cosmetic?

Depends on the make of tyres , some tyres have more grip than others the tend to use more fuel , winter tyres whilst working better at lower temps arent as grippy as most summer tyres hence better on fuel

Pick the right summer tyres and you can have the same mpg year round

The 205/55/16” is also 10% narrower than the 225/40/18” therefore there will be 10% less rolling resistance on two otherwise identical tyres.

Tyre drag is about 10% of total drag, so dropping from 225s to 205s should only actually offer about 1% fuel economy on those grounds. Of course, the nattower tyres are probably also lighter, and may reduce air resistance.

In fact I have 215/55/16 winters, not 205. The circumference is closer to the 225/40/18s. I imagine the width will be closer too.