Tyre change, better MPG?

[Shadeyman]

A few weeks ago I changed the tyres on our Multiwagon from 215/45/17 to 225/45/17(F1 Eagle GSD3) and the average MPG has gone from 45 to 48.
Could this be due to the tyre change or is something else causing better MPG?

 

[herpsuk]

Its all down to tyre pressures, tread/wear on the tyre, size of the tyre, make/brand of tyre. They all effect your mpg for better or for worse. Looks like youve got it right this time.

Maybe your pressures were out last time?

 

[Shadeyman]

In the 215/45/17 it used to be 34 in the front and 32 in the back but when I had the 225/45/17 F1's fitted the guy recommended 36 in the front and 34 in the back. The average MPG has slowly increased since.

I wondered if changing from 215 to 225 could have any impact on the MPG?

 

[Rawb]

In the 215/45/17 it used to be 34 in the front and 32 in the back but when I had the 225/45/17 F1's fitted the guy recommended 36 in the front and 34 in the back. The average MPG has slowly increased since.

I wondered if changing from 215 to 225 could have any impact on the MPG?

Theoretically changing from 215 to 225 will have a slight effect on the MPG, because of the larger surface running along the road, causing friction and drag?

I doubt the difference will be that noticeable though.

 

[dronenrs]

also dont forget some tyres have been designed with rolling resistance in mind. e.g these eco tyres. so in theroy yes it can give you better MPG

 

[BlueDan]

Knackered two of my Cinq's wheels on a pothole a while back. Got a set of four wheels off eBay with accelera tyres, fitted them all together and I'm now getting a few more MPG (was Nankangs all round before).

 

[Shadeyman]

I'm really surprised that as much a 4mpg can be gained just by changing tyres.

 

[ChrisUK]

Michelin make tyre especially aimed at high mileage and economy which is a very hard compound and low friction tread pattern which has been proven to give similar gains.

It's probably a combination of all sorts of things in your favour IMO.

 

[DaveMcT]

I've never had Michelins since the Citroen BX back in 1988. It was like a skateboard and the fronts would always spin up if you need to turn right or get onto a traffic island quickly. Driving in the wet was hopeless - yes it stopped ok but you could not turn right with any sort of brisk acceleration (the wheels just spun) so had to wait, & wait, & ... zzz

And! The fronts wore out in 20,000. I replaced with F1s and they were 60% worn at 20,000 when I sold the car. More grips AND more tyre life. Any savings in fuel were lost in chewed tyres.

 

[Hellcat]

Michelin make tyre especially aimed at high mileage and economy which is a very hard compound and low friction tread pattern which has been proven to give similar gains.

It's probably a combination of all sorts of things in your favour IMO.

But he's fitted Goodyear Eagle F1s


Perhaps the warmer weather has increased engine efficiency and reduced electrical useage.

 

[Shadeyman]

I thought warmer weather decreased engine performance a little due to low air pressure?

 

[BlueDan]

I would have thought:

Warmer air is less dense, so less to push through.
Tyres and the air in them would expand (marginally) more, if tyres are over-inflated there is slightly less in contact with the road - so less friction to overcome.

But

More a/c use (if applicable) would use more fuel.
Warmer tarmac and tyres will stick better, resulting in more friction to overcome, opposite for cold weather.
Colder air would be more dense, resulting in better combustion.

This is just random crap falling out of my brain, though, and could be a load of arse gravy.

 

[Shadeyman]

arse gravy

I think there's just too many variables to know exactly why I'm getting better MPG after a tyre change.
Its nice to think they do make a difference but maybe they dont? :shrug:

 

[DaveMcT]

To Hellcat :
then read post #9

Michelin make tyre especially aimed at high mileage and economy which is a very hard compound and low friction tread pattern which has been proven to give similar gains.

 

[Most Easterly Pandas]

I would have thought:

Warmer air is less dense, so less to push through.
Tyres and the air in them would expand (marginally) more, if tyres are over-inflated there is slightly less in contact with the road - so less friction to overcome.

But

More a/c use (if applicable) would use more fuel.
Warmer tarmac and tyres will stick better, resulting in more friction to overcome, opposite for cold weather.
Colder air would be more dense, resulting in better combustion.

This is just random crap falling out of my brain, though, and could be a load of arse gravy.

I'd agree with above, but people moan they get worse mpg in the cold winter months. I can't see how though.

 

[Stu DemonD]

I'd agree with above, but people moan they get worse mpg in the cold winter months. I can't see how though.

Letting their car idle for 10 minutes or so before driving off, whilst getting the windscreen defrosted and the interior toasty?! Not something I do personally...

 

[Venters]

Letting their car idle for 10 minutes or so before driving off, whilst getting the windscreen defrosted and the interior toasty?! Not something I do personally...

 

[Shadeyman]

Letting their car idle for 10 minutes or so before driving off, whilst getting the windscreen defrosted and the interior toasty?! Not something I do personally...

I do that every morning before I put the kids in the car to take my son to school.

Over the last few weeks the sun has been shinning and I still let it tick over ...

 

[Most Easterly Pandas]

Letting their car idle for 10 minutes or so before driving off, whilst getting the windscreen defrosted and the interior toasty?! Not something I do personally...

Quite possibly I suppose. Hadn't thought of that.