[oldeguy]

This has bugged me for awhile, and I can't seem to get a straight answer. What difference does wheel and tire diameter make? Why is a 16" tire better than a 15" tire, not including profile.

[Canadian ST]

If a 15 tire has the same profile and width as a 16 tire I don't think there is any real difference. In fact the 15in tire would give you a little more acceleration because its smaller and lighter (if the are both made by the same company) the 16in tire would give you more top end speed because it is a little bigger (as long as your engine can move it) Hope that helps.

[dBlast]

First of all if you are changing tire and wheel sizing the overall diameter (rolling circumference) or total height should remain the same for proper speedometer reading and gearing. If you are going from a 15 inch wheel to a 16 inch wheel, you will have to go to a lower profile tire to match the stock diameter.

It depends what you want. Lower profile tires will give you better cornering performance. Taller profile tires will give you more comfort. If all you want is to go fast in a straight line then a smaller wheel will give you more speed since wheels weigh more than tires.

Below are some links to help you with tire sizing:


link to focus friendly tire size chart

good tire size calculator

[ZTWsquared]

Not including profile, the criteria to consider are brake clearance and aesthetics.

As was said earlier a lower profile will likely give you a slightly different cornering feel.

oldeguy,Sep 19 2007, 10:42 AM Wrote:This has bugged me for awhile, and I can't seem to get a straight answer. What difference does wheel and tire diameter make? Why is a 16" tire better than a 15" tire, not including profile.
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[CanadaSVT]

oldeguy,Sep 19 2007, 09:42 AM Wrote:This has bugged me for awhile, and I can't seem to get a straight answer. What difference does wheel and tire diameter make? Why is a 16" tire better than a 15" tire, not including profile.
[right][snapback]249078[/snapback][/right]

Bigger footprint on the road for braking :unsure:

[naz]

oldeguy,Sep 19 2007, 02:42 PM Wrote:This has bugged me for awhile, and I can't seem to get a straight answer. What difference does wheel and tire diameter make? Why is a 16" tire better than a 15" tire, not including profile.
[right][snapback]249078[/snapback][/right]

i personally don't think bigger diameter wheels are necessary better. i think the ideal wheel is one that will let you just clear the caliper and mount the widest tire your fenders can handle since that setup will be lightest and have cheaper tires

most ppl will say that lower profile tries will handle better because of stiffer sidewall but i that reasoning goes out the window when you talk about pure summer tires like the falken azenis sport. the sidewall is just crazy stiff on that tire (and similar tires) i ran a 60 series (195/60/14) azenis sport tire on my integra and the sidewall never rolled over during autoX and hard street driving..

personally i think there is no advantage a larger diameter wheel other than looks and ability to fit a bigger brake setup

for what it is worth on my wrx wagon i have 225/50/16 tires on the stock wheels and other guys with bigger tires on their wagons have 225/45/17 or 225/40/18 tires.. they don't have any more contact patch.. their sidewalls probably aren't any stiffer.. their wheel/tire combos are heavier and more expensive.. the only thing better is their cars have nicer looking wheels