tires, tires, tires...

FrankoLaMoya · Mon Jul 27, 2015 3:25 pm

Hey guys...I need summer tires. I always liked the Michelin brand so I wanted to get some Pilot Sport A/S 3. I've noticed some brand new Michelin Primacy MXM4 on sale for a lot cheaper. ($200 difference). The problem is the size... my original dunlops were 235/45/R18 and the Primary are 235/40/R18. Not much of a difference right? Well it is still -3.5%. Do you guys believe I should buy the tires anyway or just stick with the Pilot Sport A/S 3 for $200 more??

Tire Size Comparison

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
235/45-18 4.2in 13.2in 26.3in 82.7in 766 0.0%
235/40-18 3.7in 12.7in 25.4in 79.8in 794 -3.5%

What's up with all the shoes threads anyway??

WESHOOT2 · Mon Jul 27, 2015 3:50 pm

If you check on TireRack.com the OEM Dunlop tires show 794 RPM.......

FrankoLaMoya · Mon Jul 27, 2015 3:54 pm

Hey WESHOOT2...not sure to understand what you mean by 794 RPM...?

Mon Jul 27, 2015 6:17 pm

FrankoLaMoya wrote:Hey guys...I need summer tires. I always liked the Michelin brand so I wanted to get some Pilot Sport A/S 3. I've noticed some brand new Michelin Primacy MXM4 on sale for a lot cheaper. ($200 difference). The problem is the size... my original dunlops were 235/45/R18 and the Primary are 235/40/R18. Not much of a difference right? Well it is still -3.5%. Do you guys believe I should buy the tires anyway or just stick with the Pilot Sport A/S 3 for $200 more??

Tire Size Comparison

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
235/45-18 4.2in 13.2in 26.3in 82.7in 766 0.0%
235/40-18 3.7in 12.7in 25.4in 79.8in 794 -3.5%

What's up with all the shoes threads anyway??

What kind of tires are you looking for? Both you mentioned are All Season tires. The Pilot Sport A/S 3 are Ultra High Performance All Seasons while the Primacy MXM4 are Grand Touring All Seasons. Neither are technically considered "Summer tires" which are more focused on maximizing dry road grip because the tread is not designed to grip snow or ice at all.
Between the Pilot Sport A/S 3 and the Primacy MXM4, the Pilot Sports will have considerably better grip. After all, it's a UHP tire. The Primacy series are not UHP but "Grand Touring" type of tires which focus on a quieter and more comfortable ride. They don't have the grip of UHP tires but offer a more refined ride with usually longer tread life. UHP A/S tires are more for the enthusiast looking for some moderate winter grip while GT A/S tires are more for the everyday driver who isn't really too concerned about the best grip for performance. It's basically intended for normal day-to-day driving and focused on making the ride quiet and comfortable. Basically, there are trade-offs depending on the type of tires you get and neither are technically "Summer tires" which is actually a different category of tire from "All Seasons".
http://www.tirerack.com/tires/types/tiretype.jsp

Mon Jul 27, 2015 6:38 pm

FrankoLaMoya wrote:Hey WESHOOT2...not sure to understand what you mean by 794 RPM...?

Tires have different actual dimensions despite have the same nominal measurements. It's better to go by the actual tire diameter for accuracy, but minor differences are likely negligible.

Having said that, I think 235/40/18 are too small.

235/45/18 Dunlop SP Sport 7000 are 26.3" in diameter (794 revs/mile): http://www.tirerack.com/tires/tires.jsp ... mpare1=yes

235/40/18 Michelin Primaxy MXM4 are 25.4" diameter (819 revs/mile): http://www.tirerack.com/tires/tires.jsp ... mpare1=yes

Fritz2 · Tue Jul 28, 2015 1:57 am

FrankoLaMoya, if your car is awd, 3.5% is ok as far as the mechanicals are concerned, but after they wear down the % will be higher and could theoretically mess with the awd. At least I think that's what I'm reading on the g37 forum about their awd. Could be worth researching.

Fritz2 · Tue Jul 28, 2015 2:36 am

Ignore my last post about %, that is about different wheel and tire size front to rear. Oops, my bad! As Roseanne Roseannadanna would say-"Nevermind!"

Tue Jul 28, 2015 5:53 am

Fritz2 wrote:FrankoLaMoya, if your car is awd, 3.5% is ok as far as the mechanicals are concerned, but after they wear down the % will be higher and could theoretically mess with the awd. At least I think that's what I'm reading on the g37 forum about their awd. Could be worth researching.

I believe this is the case when front and rear tires are different sizes

Woodie · Tue Jul 28, 2015 10:54 am

They're almost an inch shorter. Gonna look goofy and reduce your gas mileage significantly. Probably improve acceleration though. I went the other direction, got 245/45-18's, a smidgen wider and taller.

FrankoLaMoya · Tue Jul 28, 2015 12:26 pm

I am not really looking for summer tires. Just comfortable/not noisy summer or all-season tires. I don't care about the best grip. I am working 15 minutes from home (traffic at 40-50 km/h with like 10 stops/lights). Unfortunately, I do not take my Kizashi for a ''spin'' often.

I will probably go with the General G-Max AS-03 as I heard better review from them than the BFGoodrich G-Force Comp-2 and they are less expensive. I am also thinking about the Michelin Pilot Sport A/S 3. I will stick with the original size of tires (235/45/R18). What do you guys think?