Hi. I only have one set of wheels, am looking for a new set of street/track tires, and am unsure of which size to get. My car ('92 Accord) has a 2000 Prelude drivetrain and if I recall correctly, that car uses a 205/55-16 tire. Right now I'm using a stock Accord size of 195/60-15. According to miata.net's handy tire calculator (http://www.miata.net/garage/tirecalc.html), my speedo is already reading ~2.7% fast (indicating 60 when I'm going ~58.4).
I was planning on getting a 205/55-15 tire, the widest tire I can fit on my OE 15x5.5" wheels and closest to the stock Accord tire radius. I figure the smaller radius from the stock Prelude size tire will aid acceleration a bit. However, I'm also considering a 205/50-15, for the tire choices in this size are vast. The problem here is my speedo would read ~7.3% high (60 when I'm going ~55.6) when compared to the stock Prelude tire. My concern is not only the speedo inaccuracy, but also too much under-gearing. I figure while smaller radius tires often aid acceleration by effectively reducing "gear" ratios, there must come a point at which too small a tire hinders acceleration due to the decreased top speed in each gear. So do you think running a 205/50-15 on a drivetrain that usually uses a 205/55-16 is going too small for a daily driving tire?

In summation: I'm trying to decide on getting either a 205/55-15 or 205/50-15 for a drivetrain that usually uses a 205/55-16.

Many thanks for advice.

 

16s = too big/excess rotational unsprung mass

You won't see too many serious track people running on 16s on our cars because there is no advantage to them. You can get the same basic profile on a 15 it just doesn't look as tite.

Also - you are much better off getting separate wheels/tires for track duty. It affords you more options since they aren't required to perform 2 different services which often times conflict with each other.

 

Not to reply for him, but it's not a serious track car, but one that's going to be used at some driver education events, and with no rollover protection. (which I'm considering now) Dave probably wants to use street tires on the track at this stage. The problem with Hondas is that they come with awkward sized tires from the factory. It's almost as bad as my co-worker's Escort GT which uses a 15x5.5" wheel with a 185/60-15, of which only Goodyear makes tires for. And yes, it would be on the stock Accord 15" wheel for now.

 

I am not saying he shouldn't run street tires. What I am saying is he should get a separate set of wheels/tires for it. The awkward sizing just further compounds the need to do so since he can get a better sizing that way. You can pick up a set of 15x7 wheels for around $75 each. The 16s will make the car feel very sluggish in comparison.

 

Dave, you ever thought of a set of prelude wheels like mine? Remember, I am running the 5th gen setup too.. And I still need lower gearing with my 225/50/15 tires (pretty much the same as 205/55/15) Do not go with 16".. And I highly doubt you can go to too small of a tire with the high 5th gen gearing..

Dave, if your interested, I might be willing to sell a set of my 15.5lb prelude wheels.. 15"x6.5"

 

One minor thing . . . . Stock prelude size is 205/50-16 (24.07" diameter). So that size would work the best, assuming you've got 16 inch wheels. And it's also quite close to the stock accord radius (24.21" diameter).

But a 205 width on a 5.5" wide wheel is pushing it. Your sidewalls will be bowed, decreasing the contact patch, and negating any benefit you got from going to a wider size. 205 width on the stock integra wheels (6") is as much as you want to go. You'll get much better handling by going to at least a 6.5" width (stock prelude), and even better with a 7" width.

You can find some pretty lightweight 16X7 wheels that aren't too expensive (Kosei K1's come to mind - 15 lbs?).

Since I wouldn't recommend a 205 width on a 5.5" wheel, I'd say the 195-60-15 size that you've got on now is your best bet with the wheels you've got . . . .

Probably not the answer you want to hear, though.

By the way, the formula for determining tire diameter isn't all that hard - and I don't like trusting someone elses math/programming

Section Width/25.4 = width in inches
Width in inches * Aspect ratio = sidewall height
(sidewall height * 2) + wheel diameter = tire diameter


[Modified by Daemione, 11:47 AM 11/6/2001]

 

Thanks guys. I would never get a wheel above 15" in diameter. Eventually I'll get another set of 15's, but for now I'm trying to spend as little as possible and therefore just get some good tires for my current OE 15x5.5s. I'm just weary of the overly reduced gearing of a 205/50 over a 205/55. My engine is already spinning uncomfortably fast at highway speeds in 5th. Ideally I'd just go with the 205/55-15, but tire choice is so limited compared to the 205/50-15. I guess I'll go with the 55 series for now (99% street) and get 50 series when I get a dedicated set of track wheels/tires.

Oh, and the manufacturers of all the 205 tires I'm looking at give the okay for a 5.5 inch wide wheel, although of course it is far from ideal. Believe me, if I could afford wheels right now, I would get them.

 

Oh holy cow, so the 5G Preludes have a 205/50-15, wow so my current 195/60-15 is actually a larger radius. Hmmm I guess 50 series it is then.

 

I think I edited my post while you were responding . . . . sorry

I think my main point is that the 205 width will not be of benefit with a 5.5" wheel. You'll have more tire rollover, less grip, & uneven wear. Better (and cheaper) to stick with the 195/60 size.

But I understand how tire availability can affect the decision.

 

Thanks for the input. I dunno. I figure that although they'd have the same sidewall "height," the 55 series tire would have a stiffer/more robust sidewall than a 60 series tire, which would deform less and increase my turn-in feel and transient response. I'm not looking for more grip, just better steering response. Plus the 205/55-15 has just an ever so slightly smaller rolling radius and like you mentioned is actually closer to the stock Prelude radius compared to the 195/60-15. A little added zip to my already quick people hauler.