Same alloys, narrower tyres?

Encoder1970

Time to change tyres again.
I'm currently on 20560R15 on my alloys but in an effort to lessen my mpg I'd like to put narrower tyres on (not sure this will actually help but...).
Can I fit narrower tyres on the old alloys, retaining rim width?
I'm thinking 19560R15.

neilthefunkeone

Yep.. stretches the tyre walls though.. not sure if it firms up the ride or what damage it does to the wall..

hi_im_fil

You'll barely notice the stretch though. It won't look anything like the pic above! That pic is a really stretched tyre.

Anan1

I wouldn't bother, I thiunk the difference will be negligible. If you do change you'll need 195/65R15 to preserve the existing sidewall height.

peasant

pump them up about 0.5 bar above manufacturers specs, that'll do the trick

Esel

peasant wrote: »

pump them up about 0.5 bar above manufacturers specs, that'll do the trick

Are you serious? That's 7 lbs psi extra.

si_guru

esel wrote: »

Are you serious? That's 7 lbs psi extra.

7 psi is nothing... about as much as you would add to tow a trailer or go fully loaded.

kirving

Could be about 20% above recommended. Wouldn't that affect ride comfort, and more importantly stopping distances for the sake of possibly a few more mpg?

Avns1s

Kevin Irving wrote: »

Could be about 20% above recommended. Wouldn't that affect ride comfort, and more importantly stopping distances for the sake of possibly a few more mpg?

Correct on all counts plus your tyre will last just aboout half as long, and wear in the centre.

False economy and bad practice to overinflate the tyres.

Recommended tyre pressures are there for a reason.

peasant

Avns1s wrote: »

Correct on all counts plus your tyre will last just aboout half as long, and wear in the centre.

False economy and bad practice to overinflate the tyres.

Recommended tyre pressures are there for a reason.

Naaah ...been doing it for years without any negative effect.

Manufacturers recommendations always err on the side of comfort.

Pumping up your tyres makes them a bit harder (but your car is supposed to be suspended by the springs, not the tyres), but they last longer, are more resistant to potholes, steering and braking are not affected (as long as you don't over-do it) but rolling resistance (and therefore mpg) is

kirving

If rolling resistance is affected, it stands to reason that stopping distance is. They're both based on the friction between the tyre ane the road.