Smaller sidewall tire size

Thanks Dave. The better handling characteristics seems to be a consistent report. I wonder how much of the MPF hit was from the wider stance. Hey, I really like that tire size calculator! That is very helpful. Thanks.

 

Yeah, a LRR tires seems to be the better long term play. But I am wondering especially about the effect of the width of the tire on MPG. I have heard some say there is no difference in MPG from the 185 to the 205. But others have indicated there is a difference. But it's hard to measure when the kind of tire changes too I guess.

 

Steve, I actually got a significant improvement going from 195's to 205', but I believe much of this improvement "not all" was down to the choice of tyres.

Another thing to consider is how much motorway/freeway driving you do as the improvement may be less the faster you go, "at the speeds that aerodynamics really begin to take effect" at lower speeds you will gain more from the lower rolling resistance of the wider tyres. Another effect of the wider tyre is that you will not slow down as much when taking bends, therefore not loosing as much inertia and again saving fuel. Every little bit adds up.

John (Britprius).

 

John, so you're saying the 205 tire will get better MPG than the 185, all other things being equal? A wider stance doesn't increase the amount of rubber on the road and therefore resistance? I have heard the argument that the wider tire is not adding rubber to the road as the car weight is the same but carried over a wider stance thus with less rubber on the road from front to rear of the contact area. If the result is very similar amount of rubber on the road, then the question comes to mind, why a savings then? What factors result in any possible increase?

You mention a couple of other factors. Do wider tires have a lower rolling resistance, all other things being equal? And why would wider tires not slow as much in a turn, maybe they don't roll toward the sidewall as much, that would increase resistance? It all sounds very minimal in the effects. Or is there more than I am considering? Likely so.

But thanks for the great info.

 

Steve in the UK the rolling resistance of tyres now by law has to be measured against a standard rating along with wet grip and noise, and published at the point of sale so that true comparisons can be achieved .

I do not profess to fully understand how the width of a tyre affects the rolling resistance but would imagine the amount of deflection of the rubber and casing of a given size tyre carrying the same weight reduces as the width increases causing less squirming of the tread on the road surface and saving energy and ware.

The speed at which you can take a turn is purely down to the fact that the car feels much more stable at a given speed and is able to take bends faster without that feeling of being on the edge of grip so that you do not slow as much for a given bend.

If you wish to thank someone for a post or information click on the "like" on the right a the bottom of that post. This is the best way of saying thankyou.

John (Britprius)

 

It is an interesting subject. Thanks for your input John. I forget to click on Like so thanks for the reminder.