Tire size substitution

[dapqam]

I purchased 235/70-18 Michelin CrossClimate 2 XL tires for my 2017 Acura RDX Tech package. They are not in stock right now and they asked if I want to substitute 245/70-18 tires which are in stock. The 235's are h rated and the 245's are V rated as well as being 10 mm wider. Do you think the 245's would be noticeable stiffer riding? Sincde they are wider and V rated. I suspect they would be and I want a smooth riding tire.

[Stealthee]

The tires are also 1/2 taller. Do you have the clearance for the height?

[RidingOnRailz]

Originally Posted by dapqam

I purchased 235/70-18 Michelin CrossClimate 2 XL tires for my 2017 Acura RDX Tech package.
They are not in stock right now and they asked if I want to substitute 245/70-18 tires
which are in stock. The 235's are h rated and the 245's are V rated as well as being
10 mm wider. Do you think the 245's would be noticeable stiffer riding? Since they are
wider and V rated. I suspect they would be and I want a smooth riding tire.

A generalization or two:

Higher speed-rated tires(H & V) can ride slightly stiffer/firmer/ rougher/choose your poison! than lower speed-rated(S or T for instance), given the same cold tire pressures. It also depends, to a degree, on tiremakers' proprietary blend of herbs and spices(!) and rubber compounds going in.

The wider variants offered in your case will also lend slightly more sensitivity to steering inputs, if handling is your thing.

Question: Is the first size you indicated the OEM for your vehicle? If so, and if your current tires are in still serviceable condition(tread still above the warning strips, not too many dry cracks, etc) then I would wait for that size to come in, and have them put on. Never let a tire dealer offer to put just anything on your rolling investment. Replace size-for-size, unless you're doing a proper Plus- or minus-sizing of your wheels & tires.

The half-inch height difference mentioned above can also have implications for speedometer/odometer accuracy. Generally accepted height variation is no more than quarter inch, on passenger cars, crossovers, and light trucks.

[CapriRacer]

First, the differences in size is relatively small compared to the differences between tires (meaning make/model). So if you wanted a particular make/model and they offered it in a slightly different size, the difference would be minimal.

HOWEVER, the speed rating could be an issue as they may design the two tires differently. On the other hand, maybe not.

[RidingOnRailz]

Originally Posted by CapriRacer

First, the differences in size is relatively small compared
to the differences between tires (meaning make/model). So
if you wanted a particular make/model and they offered it in a
slightly different size, the difference would be minimal.

HOWEVER, the speed rating could be an issue as they may
design the two tires differently. On the other hand, maybe
not.

Respectfully disagree. I guess I'm actually pickier than the tire engineer on here. I still recommend holding out for a size-for-size replacement.