eddie jr

My understanding was always that a big part of the idea of z-rated tires and being able to handle speeds is that the sidewall is a lot stiffer for better control and response. A friend just bought some 245/50/16 Firestone Wide Ovals for his GTA (which have very good reviews) and i noticed 2 things:

1. When you push sideways on the car, the car still "wiggles" a fair bit (due to sidewall flex) and really didn't seem that much different from the 15" T rated 235 tires i still have on mine.

2. When he went around the same off-ramp he only really got at most 5kph faster before hearing tire chirp and his springs should be even a bit stiffer (TPI WS6 car vs my F41/Y99 V6 almost WS6 save the rims and springs).

In reading reviews it sounded like these tires are very good for handling and traction. Does this seem weird? I would have thought it would be night and day between a WS6 car with good tires and my current setup? We even rebuilt his entire front-end beforehand too including struts but excluding springs. I am very curious though as i was considering these tires when i finally get around to putting on the 16" rims.

406z

Well alot more than meets the eye goes into handling. He has a v8 meaning his cars weight disribution will be different. Also, in cars more than 3 years old the up-keep on the suspension comes into play. I have firestone firehawks on my car and they do alright, but I don't push my car on the road, because I run stock width tires on the back, and lack a performance suspension currently.

There are alot of tire options out there. You might be better getting a nice all season tire that will last a long time for your v6. That way you can put the money saved into actual suspension upgrades or what ever your car needs.

Camaro5690

iTrader: (1)

I dont know why everyone is still spouting Z-Rated stuff around. Z rated tires were the best with the old rating system. Now theres alot of different ratings. I have W-Rated Tires meaning they are good for 168mph (Where do they pull these numbers from?) I myself have never heard of there being a stronger sidewall on higher rated tires. If you want a stronger sidewall I believe theres a company that makes tires with carbon fiber reinforced sidewalls.

AlkyIROC

Z rating is a speed rating. There's a lot more numbers on a sidewall which mean a lot more so 2 different Z rated tires will perform and handle differently. Although there's always bragging rights about having Z, W or Y rated tires on your car but unless you're running sustained high speeds where they're needed, it's an unneeded extra expense.

Here are a few links about ratings and numbers on the tires

http://www.tirerack.com/tires/tirete....jsp?techid=35
http://www.tirerack.com/tires/tirete....jsp?techid=33
http://www.tirerack.com/tires/tirete....jsp?techid=48

T rated tires are good for sustained speeds up to 118 mph (190 KPH). All the speed ratings are at weird MPH numbers because they're based on KPH ratings which go up as even numbers. Speed ratings mean nothing for dragstrip racing because it's a short spurt. If you were racing in the Silver State Classic, you would need the proper speed rating depending on what class you were in. For legal north american highway speeds, every speed rating available exceeds the speed limit.

91_5.7_TPI

iTrader: (2)

You need to look at the treadwear, traction, and temperature ratings when you are buying tires for handling. The treadwear number (the lower the better) indicates whether the compound is hard or soft. Soft compound tires have more grip, generally. You want AA traction and A temperature. Normally, these features are found on Z rated tires and up. Unless you are actually planning on running past ~150 for extended periods of time, you don't need anything more than Z rated or any other high-speed rated tire for that matter.

What components did you use in the rebuild? (ie, shocks, etc) If you used cheap shocks/struts, the car won't handle much better than it would before. As was mentioned before, the V6 in your car both weighs less and the weight sets further back, therefore giving better weight distribution. Several other factors come into play. Maybe he's less comfortable with his car than you are. Just because the tires squeal doesn't mean that the tires are close to failure. My 245/50R16 Bridgestone g009s squeal later than my 275/40ZR17 BFGoodrich g-Force Sports, but they don't stick nearly as well (or handle heat, lol).