Tyres and petrol consumption

[51315]

If I under-inflate tyres by 2psi for a less bumpy ride (Goodyear Efficient Grip Performance) what % increase in fuel consumption will I suffer? Anyone?

 

[Wighty]

If I under-inflate tyres by 2psi for a less bumpy ride (Goodyear Efficient Grip Performance) what % increase in fuel consumption will I suffer? Anyone?

Nothing you will notice buddy , go for comfort . What pressure have you reduced to ?

 

[Blobcat]

You’ll only be able to tell this yourself. If you track your fuel economy already (not from the dash) then drop the pressures and see the difference.

I can see the reduction in fuel economy from summer to winter tyres (there’s also the cold weather longer warm up affect)

 

[51315]

Nothing you will notice buddy , go for comfort . What pressure have you reduced to ?

Reduced to 27 psi from normal 29 psi.

 

[Wighty]

Reduced to 27 psi from normal 29 psi.

I don't know how much different cars and different wheels allow different pressures , but neither of mine would be under 30psi front and 32/33 rear.
Be interested to hear what anyone else thinks , it sounds a bit low at 27

 

[LostKiwi]

That does sound a bit low. What size tyres are you running?

If you run them too low you run the risk of heat delamination in the sidewalls.

 

[51315]

I don't know how much different cars and different wheels allow different pressures , but neither of mine would be under 30psi front and 32/33 rear.
Be interested to hear what anyone else thinks , it sounds a bit low at 27

For W169 - 2009 A Class 160 unladen pressure is 29psi front and rear.

 

[51315]

That does sound a bit low. What size tyres are you running?

If you run them too low you run the risk of heat delamination in the sidewalls.

195/55R16 Goodyear Efficient Grip Performance 87H.
Petrol lid says unladen 29psi all round.

 

[LostKiwi]

Ah ok 27 will be fine then. The bigger MBs run much higher pressures.

 

[sonic]

You’ll only be able to tell this yourself. If you track your fuel economy already (not from the dash) then drop the pressures and see the difference.

I can see the reduction in fuel economy from summer to winter tyres (there’s also the cold weather longer warm up affect)

I see an improvement summer to winter tyres. But I change from 18" to 17".

 

[Blobcat]

I see an improvement summer to winter tyres. But I change from 18" to 17".

I’ve never had an improvement going summer to winter as the rolling resistance of the winters is significantly higher than the summers.

 

[sonic]

I’ve never had an improvement going summer to winter as the rolling resistance of the winters is significantly higher than the summers.

Defiantly better for me but only for a month after changing, when still not cold.
I normally change mid Oct & mid April. I am sure the smaller tyre makes the difference.

 

[Dean Fletcher]

I don't know how much different cars and different wheels allow different pressures , but neither of mine would be under 30psi front and 32/33 rear.
Be interested to hear what anyone else thinks , it sounds a bit low at 27

What size tyres do you have?

 

[Gazwould]

If I under-inflate tyres by 2psi for a less bumpy ride (Goodyear Efficient Grip Performance) what % increase in fuel consumption will I suffer? Anyone?

Bumpy ride - renew dampers .

 

[John Laidlaw]

1.44756%

 

[keefysher]

Defiantly better for me but only for a month after changing, when still not cold.
I normally change mid Oct & mid April. I am sure the smaller tyre makes the difference.

I normally change from summer tee shirt, shorts and Teva's to jeans, sweatshirt and trainers mid Oct & Mid April too. But keep the same tyres year round

 

[Wighty]

What size tyres do you have?

CLK , winters are 205 55 16 , summers are 225 40 17 front , 245 45 17 rear (ish ?)
E Class , 225 55 16 winters , 245 45 17 summers

 

[Dean Fletcher]

CLK , winters are 205 55 16 , summers are 225 40 17 front , 245 45 17 rear (ish ?)
E Class , 225 55 16 winters , 245 45 17 summers

Mine are 245/35/18 front and 255/35/18 rear. Rear is 36psi and 35 front. Its says if the car is fully packed put them up to 40psi Haha

 

[Rotorhead500]

1.44756%

I see you rounded up there John, presumably to shorten your post???

 

[John Laidlaw]

I see you rounded up there John, presumably to shorten your post???

You saw that then Guy!