Looks like I may be keeping GP 1512 rather than selling it, so I'm off to make the ride more like I want it (more compliant). I've been researching wheel/tire combos and it looks like 16 inch may give me the best combination of ride quality, choice of tires and decent performance. I looked at 15" but there don't seem to be many choices in that size.

Here are OEM tire specs:

Dunlop Sport 01 DSST 205/40-18
Diameter: 24.4" Revs/mile: 840, section width: 8.3" (Based on 7.5 Wheel width")

I'm currently running:

Toyo Proxes 4 205/40-18 - (Based on 7.5 Wheel width")
Diameter: 24.5", Revs/Mile: 847, inflated width: 8.7"

I prefer to not lower the car any further with a smaller tire diameter due to the frequent scraping of the flexible splitter flap at current height. I understand the JCW suspension on the GP results in lowering over stock height of about .6".

I am considering the following sizes:

Wheels: 16x7 or 16x6.5 with offset of approx 37-44mm. As I understand it, I am better off going towards the 44mm offset spec so the tire will not rub on the outer fender lip.

Tires:
205/55-16 is appealing to me as it is slightly taller than OEM spec (less scraping of the front splitter flap), but Alex at the Tire Rack is recommending the 205/50-16 as a safer choice as there is a chance for rubbing at the top of the wheel well with 205/55-16.

Looks like 205/50-16 would fit with no issues, but gives me a lower height and greater difference for revs/mile.

Example specs:

Dunlop Direzza Sport Z1 StarSpec:
205/55VR16 - Diameter: 24.9", Revs/Mile: 837, Sec Width: 8.4" (Based on 6.5" Wheel width)

205/50VR16 - Diameter: 24.1", Revs/Mile:865, Sec Width: 8.3" (Based on 6.5" Wheel width)

If I go with a 205/50-16 is there a way to adjust the speedometer to be accurate?

Any advantages/disadvantages to 6.5" vs. 7" wheel width?

Any other opinions/recommendations?

Thanks,

Lee

 

Going with the 205/50 may be a better choice to due easier tire sizing. The 55 ratio only comes in like 3 or 4 different tires with the 50 having a lot. If I remember correctly, with the slightly different sidewall, the speedo will only read maybe 2 or 3 MPH slower than what it actually is. The mileage will still read correct because it's digital. The speedo probably is computer controlled, too (is it?). PM MiniHune or any of the other tire Gods in here (Alex @ Tire Rack) with questions.

 

Why 205 not 215?

 

Thanks.

On tirerack.com I found (47) 205/55-16 vs. (19) 205/50-16 tires listed in the Summer category group, excluding Track and Competition and Run Flat tires.

The speedo and odometer inaccuracy result would be the same I think - it's based on how many wheel rotations there are as far as I know.

Lee

 

I found 3 tires in 215/50-16 Summer category, excluding competition and run flats.

I see the General Exclaim UHP is one of them and it has a good ride comfort rating - could be a possibility. I've seem mixed reviews on these.

Thanks,

Lee

 

As a daily driver, my GP is fitted with 16x7 silver Minilites and (German) 205/50/16 Goodyear Eagle F1 GS-D3s inflated to 36-38 psi. Excellent grip, handling and ride! Just a hint of strut tower deformation (mushrooming) after 20k miles. Ireland fixed camber plates will likely be installed when the tires are replaced. With the transfer of Goodyear production to China, it will be interesting to see how the new F1s perform... Due to the lowered ride, the front strakes were removed---not a major detriment for city driving!
Cheers!

 

Lee,

You have other options.

To me, the GP is special. And the GP wheels are part of that look.
A look that I'd suggest is worth keeping.

Moving to 16" wheels is possible, practical, functional. Using 205/50-16 makes the most sense.

I'd say unless you find a wheel that you really love, most 16" wheels would detract from the overall GP look.

As a result, If you want to keep the GP wheel you can consider a better tire in 205/40-18 than either the runflat or the Toyo Proxes 4 (Ultra HP All Season tire). Still need to be careful about scraping the splitter.

Try checking out-
http://www.tirerack.com/tires/tires....ilot+Sport+PS2
Michelin Pilot Sport PS2 Max Performance Summer tire
220 treadwear Y speed rated 20 lbs $223 each (backorder-see Alex for dates), (alternatively 225/35-18 is possible $246 each- low stock)
Test results-
http://www.tirerack.com/tires/tests/...y.jsp?ttid=101

PS2 are expensive but one of the very best street tires, worthy to be put on a GP like yours. You get all the handling you want or need and good street manners.

Also in 225/35-18
Goodyear Eagle F1 Asymmetric Extreme Performance Summer tire (also worthy of a GP).
http://www.tirerack.com/tires/tires....+F1+Asymmetric
200 treadwear Y speed rated 23 lbs $211 each (low stock)

 

Thanks for the info, gort. I rented a car this weekend that has 205/55-16 tires on it and the sidewall/wheel ratio looks a little too tall to me, so if I go with 16, I think I'd like the appearance of the 205/50 better.

 

Thanks minihune - more food for thought. I lived on Maui for 18 years and try to get back about every year or so.

Aloha nui,

Lee