Tire and wheel question?
#31
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Originally Posted by y0ureviltwin
From http://www.miata.net/garage/tirecalc.html its not far off.
yep...you're pretty damn close. but like hai said...just lower it.
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Originally Posted by y0ureviltwin
I know I downgraded but costs of new tires for the 19's are just plain sick.
#35
R stands for Radial and the Z stand for the Speed Rating. Z rating covers Z, W, and Y speeds for radial tires.
Originally Posted by y0ureviltwin
I have a question about the gap on my car. I use to have the OEM 19 inch with 225/40R19 fronts and 245/40R19 Y-rated rears but just purchased a nice new set of 18 inch wheels that have tires at 225/45ZR18 fronts 245/45ZR18 rears. From the looks, my car has a wider gap between the tires and fender, is this just an illusion? Also is there a difference between 45R18 vs 45ZR18?
#36
For normal daily driving a tire's speed rating has nothing to do with safety. An H-rated or V-rated tire is just as safe as Z-rated, W-rated, Y-rated tires. Unless, you drive a sustained 130+ mph for very long periods of time on your way to work or school then you're screwed if you are using less than Z-rated tires. When it comes to tire safety, what's more important is choosing the correct load-rating for your vehicle and having proper air pressure all the time.
Originally Posted by hai109
First of all you don't need to buy michelin...They are very expensive...But Y rated tires are safer for you. I don't understand why people would not worry about their tires? Those are theonly thing that really saves you in a car...A blow out will cause you to spin out of control....
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Originally Posted by romanwarrior
For normal daily driving a tire's speed rating has nothing to do with safety. An H-rated or V-rated tire is just as safe as Z-rated, W-rated, Y-rated tires. Unless, you drive a sustained 130+ mph for very long periods of time on your way to work or school then you're screwed if you are using less than Z-rated tires. When it comes to tire safety, what's more important is choosing the correct load-rating for your vehicle and having proper air pressure all the time.
#38
Actually if there were H-rated tires in the sizes that I am running I would totally use them on my G35. You mentioned a very important word and that is "POTENTIAL." I have a Technosquare reflashed ECU and my car could potentially do 160+ mph. Does this mean I would take my car up to 160mph, 170mph, 180mph...? No! I have never taken my car upto 125mph so I have no need for Z-rated tires. A tire's speed rating has nothing to do with sidewall stiffness. The relative sidewall stiffness is about the same between H-rated, V-rated, and Z-rated tires if you are comparing the same size tires. The only time one would be stiffer than the other is when a tire has reinforced sidewalls or rated as "extra load." There are actually H-rated tires that have the same (or higher) load index and max loads as same size V-rated or Z-rated counterparts. An example is the Falken FK451 225/50R16.
This tire size comes in H-rated and V-rated, but both have the same load index of 92 and have 1,389 lbs max load. With YOUR logic, you are saying that even when you're not going 130mph the H-rated tire will collapse and not the V-rated tires because the former has a lower speed rating. That just makes me laugh. Sorry. I would take any H-rated tire that is properly inflated to 130mph than a Z-rated tire that has less than 20 pounds of air in it.
Here's another example... Falken FK451 205/50R16 V-rated tire with Reinforced sidewall, load index 91, max load 1,356 lbs. If your car came with this tire and you wanted to up-size to a 17-inch, you would have to move up to 215/45R17. Falken has a 215/45R17 tire size in the FK451 and it has a higher Z (W) speed rating but does not have a reinforced sidewall and has a lower load index (87) and a lower max load 1,201. Do you think that the Z-rated tire would have a stiffer sidewall than the smaller tire with a lower V speed rating?
The point here is ... there is no correlation between the speed rating and sidewall stiffness when comparing the same size tires that have different speed ratings.
This tire size comes in H-rated and V-rated, but both have the same load index of 92 and have 1,389 lbs max load. With YOUR logic, you are saying that even when you're not going 130mph the H-rated tire will collapse and not the V-rated tires because the former has a lower speed rating. That just makes me laugh. Sorry. I would take any H-rated tire that is properly inflated to 130mph than a Z-rated tire that has less than 20 pounds of air in it.
Here's another example... Falken FK451 205/50R16 V-rated tire with Reinforced sidewall, load index 91, max load 1,356 lbs. If your car came with this tire and you wanted to up-size to a 17-inch, you would have to move up to 215/45R17. Falken has a 215/45R17 tire size in the FK451 and it has a higher Z (W) speed rating but does not have a reinforced sidewall and has a lower load index (87) and a lower max load 1,201. Do you think that the Z-rated tire would have a stiffer sidewall than the smaller tire with a lower V speed rating?
The point here is ... there is no correlation between the speed rating and sidewall stiffness when comparing the same size tires that have different speed ratings.
Originally Posted by hai109
Yeah, but you would not want to put H rated tires on you G35. The potential of you going high speed is higher so that's the reason why they put higher speed rating on our cars. Also, the sidewalls on our tires are a lot stiffer then a H rated tire. Even if your not going 130 plus the H rated tires might not hold that well and the sidewall will collaspe...So hence its not safe to put lower speed rating tires on your car..
#40
Originally Posted by y0ureviltwin
I went from having OEM 19 inch to aftermarket 18 inch and noticed a bigger gap, the dealer who installed them said there wouldnt be any differences. The above stats came from the dealer, so I dont why im seeing a gap.
Stock
Aftermarket
Stock
Aftermarket
i didnt know matchbox made wheels that big...???
im sorry, not trying to be a dcik, i just dont think they're good on a G
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