So between a 215/60-15 and a 205/60-15 tire of the same type, which do you guys think would handle better? The 215 is slightly wider, which should be slightly more traction. But at the same time, the 215 has a slightly taller sidewall, which should mean more sidewall flexing. So do you guys think the slight width advantage cancels out the slight sidewall flex disadvantage?

 

It's a 15" tire... it will have sidewall flex. Get 17's+ if you want to eliminate flex.

 

17's are so two years ago...

Get 18's !

Rod.

 

nah, get dubs!!!!!

 

or why not go to some 225/55 15's? wider and shorter.

 

I agree. Stick to factory tire size.

205/60/15 or 225/55/15 is what you should consider.

The tiny bit of added tire width probably will not be noticable at all. What made the most difference in my 280ZX was the shocks, struts, and sway bar upgrades. You probably already have that covered.

 

The only problem with 225/55-15 is that no one makes them. Only 3 hits for that size show up on Tirerack.com: 2 of them are Competition semi-slicks, and the last is unusually expensive and not even all that great! Not unless you guys know a company that does actually make that size.

 

225/55 in Sumitomo is what I have on the rear. It is a more rare size, but if you call a local tire store I'm sure they can find a set for you.

 

What's the model of the Sumitomo? (ie "HTR", "HTR+", etc.) I just checked Sumitomo's site, and they have no 55-series tires for cars. http://www.sumitomotire.com/theline/ Maybe yours is an older/discontinued size/model.

Oh lord, I just realized what forum this thread is posted in. ^^;; I guess I clicked on the wrong one and was just too excited to post!

 

One tire size is unlikely to make any noticeable difference in your cars handling "in the real world", but it will affect your gas mileage.

Tire compound is much more important.

But, I don't put anything smaller than 225/50/15's on my car anymore...

 

Yeah, I was considering that too. The slightly larger 215/60 doesn't weight appreciably more, but does cover more distance for each revolution. I was also taking into account the slightly increased ride height, which I don't really take as a negative, considering some of the places I've been where I was glad I'm not that low; not only do I have a steep driveway, but I've been graveling on the last Zonc road trip I went on. ^^

 

I JUST changed from a 215-60-15 back to a stock 205-60-15 tire. The tires I installed were Michelin Energy models, mainly because they were available at the right price (special deal, not to be repeated) and I've always liked Michelins. They replaced Dunlop D60A2s which had been on a LONG time. Frankly, if I could have found 215's I'd have taken them in preference because I like having more rubber on the road without departing significantly from the stock tire size.

I am not a fan of departing from factory tires sizes other than going one or two sizes wider. Going to larger wheels with lower profile sidewalls results in a harsher ride, AND since you have more unsprung weight in the heavier tires and wheels it adds to the braking load and can negatively affect acceleration. Rim or sidwall damage from potholes also can be an important factor. There's also the issue of speedometer accuracy, and I LIKE having my speedo as accurate as possible.

For those reasons, I've never been fond of major departures from stock wheel and tire sizes. I suppose that if I were really motivated, I might go up to a 16" wheel and a 50-series profile, but IMO anything beyond that would be dangerous to the rims if you encounter potholes, and would ride like a brick.

Back to the question - if anything, dropping back from 215 to 205 tires improved the ride, and I seem to have gained one or two MPG in highway driving. There is no apparent difference in handling or traction that isn't attributable to the difference between the previous and current tire designs. But I haven't autocrossed the car since installing the Michelins, so I lack data.

So in terms of handling - just suit yourself. Having a bit more rubber on the road while maintaining the system close to stock is not a bad thing in my opinion.

 

225/50/15 u can also go look at

 

No, I don't really want to go with a smaller diameter. and that size has a 3.3% error difference.

 

If you're worried about speedometer error, then 245/45/16 is the only way to go!

 

yes but then you need some Simmons 3-piece 16x9 inch +0 wheels!

 

It is possible to increase the wheel diameter without significantly changing the rolling radius of the overall wheel/tire combination. It is also possible to do so without adding more weight. In fact, you can decrease the weight by going with a light weight wheel...

The 18's on my car have nearly and identical final rolling radius as the stock 14" wheel/tire combo. The effect on the speedometer is negligable at worst and the weight increase is marginal and more than made up for by the upgraded brake material and suspension components that were installed prior to changing wheel size.

To each their own, but if you're going to argue against something... Be a little more factually correct.

Rod.

P.S.

"Going 1 or 2 sizes wider" as you mentioned being one of your acceptable practices is almost always going to result in a taller or shorer tire (depending on aspect ratio)... Which will lead to more speedometer inaccuracy.

In fact, it's much easier to increase tire width and wheel diameter together and maintain a similar overall diameter than it is to find a wider tire of the same wheel fitment that isn't also either significantly taller or shorter overall.

 

^^^ You speak as though you worked in the tire industry.... oh wait, you did!

 

harsher ride is also simular to a more firm and stable ride.
The ST springs and 225/40/18 tires on the 280ZX I had did firm up the ride a lot. It was an improvement over the handling it used to have. Even so, its soft compared to my 350Z's ride... but I like it firm

 

so do u think that a 215-55-14 that i have thanks to $330 and pepboys with illuminas all the way around, eibach springs and frontand rear sways with a front strut tower bar is a good set-up? cause i have the tires on the 6spokes without the suspension and i just got it and im thinkin its gonna be totally different once i change the suspension out i mean the tires alone changed alot from a 205-70-14

 

The tire compound and sidewall construction of the tire is more important to "street" handling than physical dimensions.

What brand and model tires did you get?

 

i dont know what brand as im in virginia at work and theryre in dallas...but theyre a knock off brand of cooper (is what the guy at pep-boys said) so whatever that brand is but ive noticed a huge difference between them and the 205-70-14s that were i swear 4 different brands that i had before and still better than the same size goodyears my dad has on his z, but im stoked to get it lowered and swayed im told it will completely change the handling of the car and im wayyyyy exited to have a barely used set of illuminas ALL the way around for it too like cmas early

 

knock offs.....of coopers.......yikes......

 

I thought Cooper's WERE the bottom of the barrel... I stand corrected!

 

well looks like im sure u have a better preference?? 215-55-14 i called around and could only find about 3 types, being as theres really only 4 or 5 companies which all tires come from and i needed them that day and the others id have to order....i guess ud rather have goodyears? but seriously ive put it at 4-5k and dropped it and get a tiny chirp and im off so no complaints just would love to hear ur knowledge