Bradb Posted September 5, 2002 Share Posted September 5, 2002 Granted I know they touch the road. But with these new Kahns I getting later today. 265, 40, 18 x 2 (rears) 235, 40, 18 x 2 (front) Is what I've been advised. Does that sound cool? Whats the first number mean 265/235? Me confused. Is it the tyre width? The 40 is the tyre depth between alloy and floor 18 as in inches Sorry to be such a dolt, but I wouldn't ask if I knew the answers. Also what kinda cost can I expect to pay on tyres of this sizing? Quote Link to comment Share on other sites More sharing options...
AJI Posted September 5, 2002 Share Posted September 5, 2002 265/40/18 = 265 width (mm)/40 profile height/18 diameter (in) The profile height is a ratio between width of wheel and diameter or something like that and not just a height measurement between alloy and ground. Try http://www.etyres.co.uk for a price guide, they have an online ordering which displays final pricings. Quote Link to comment Share on other sites More sharing options...
JohnK Posted September 5, 2002 Share Posted September 5, 2002 http://www.kwik-fit.com/product/tyres/tyres01.htm put the mouse over the tyre for explanations. Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted September 5, 2002 Share Posted September 5, 2002 The 235 etc. is the width of the tyre in mm. The 40 is the aspect ratio - basically the height of the sidewall as a percentage of the tyre width. This makes a 235/40 have a sidewall height of 235x40%=94mm. Measurements are taken from the where the bead contacts the wheel rim. Quote Link to comment Share on other sites More sharing options...
Bradb Posted September 5, 2002 Author Share Posted September 5, 2002 Is it best I go for Z's? Not really when mi cars limited to 120 Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted September 5, 2002 Share Posted September 5, 2002 Get Z rated for two reasons. 1. you don't want to have to buy new tyres when you de-restrict. 2. what sort of low perfromance car uses tyres that size but doesn't need Z rating? Vitaras. Your Supra deserves better! Quote Link to comment Share on other sites More sharing options...
randy Posted September 5, 2002 Share Posted September 5, 2002 Speed Rating - Miles/Hour - Kilometers/Hour - Typical Use N=87 MPH, 140km/h, P=93 MPH, 150km/h Spare Tires Q=99 MPH, 160km/h, Winter, LT Tires R=106 MPH, 170km/h,LT Tires S=112 MPH, 180km/h T=118 MPH, 190km/h U=124 MPH, 200km/h H=130 MPH, 210km/h, Sport Sedans V=149 MPH, 240km/h, Sports Cars Z=149 MPH, 240km/h and over, Sports Cars W=168 MPH, 270km/h, Exotic Sport Cars Y=186 MPH, 300km/h, Exotic Sport Cars *Today, the Z-speed rating is the only speed rating that is still branded “within” the tire size, as in P225/50ZR16. All other speed ratings are shown in the tire’s service description. Why don't you go for the Y- rated tire as you may want to do 180+ someday! Randy:D Quote Link to comment Share on other sites More sharing options...
Bradb Posted September 5, 2002 Author Share Posted September 5, 2002 Y's it is kids.. ; Safe I'll get the Z boots. Quote Link to comment Share on other sites More sharing options...
matt Posted September 5, 2002 Share Posted September 5, 2002 I use 35 profile on the rear ....40's on the front . This helps keep the overall rolling diameter close to stock, and the speedo remains accurate hth Quote Link to comment Share on other sites More sharing options...
Bradb Posted September 5, 2002 Author Share Posted September 5, 2002 265, 35, 18 x 2 (rears) 235, 40, 18 x 2 (front) Is that what you suggest Matt, somebody else told me to go this route. Discuss Quote Link to comment Share on other sites More sharing options...
Dragonball Posted September 5, 2002 Share Posted September 5, 2002 Brad Mine are 265x35x18 Rear - (go wide as poss dude!) and 245x40x18 Front on 8.5" 's Only just got away with fronts Paul:cool: Quote Link to comment Share on other sites More sharing options...
Bradb Posted September 5, 2002 Author Share Posted September 5, 2002 Why 35 at rear and 40 at front.. Its like a reverse go cart that way? Quote Link to comment Share on other sites More sharing options...
randy Posted September 5, 2002 Share Posted September 5, 2002 Originally posted by Bradb Y's it is kids.. ; Safe I'll get the Z boots. Z- has a speed rating of only over 149mph!! W=168 MPH, 270km/h, Exotic Sport Cars!! Y- has a speed rating of over 186mph!! When Z-speed rated tires were first introduced, they were thought to reflect the highest speed rating that would ever be required. Since that time the automotive industry has found it necessary to add W- and Y-speed ratings (indicated in the tire’s service description) to identify the tires that meet the needs of new vehicles that have extremely high, top speed capabilities. While all Z-speed rated tires are capable of speeds of 149 mph and above, prior to the W- and Y-speed ratings were identified in the service, how far above 149 mph was not identified. Randy:) Quote Link to comment Share on other sites More sharing options...
Ian C Posted September 5, 2002 Share Posted September 5, 2002 Originally posted by Bradb Why 35 at rear and 40 at front.. Its like a reverse go cart that way? The 35 and 40 are percentages of the tyre width. So, 265*35 gives a tyre wall height equal to 35% of 265 = 93mm. 245*40 gives a tyre wall height equal to 40% of 245 = 98mm. Not sure how exact the measurements are, though - I thought the tyre wall heights should be the same, this working out seems to imply the fronts would be 5mm higher than the rears, but if the percentages quoted on teh sides of the tyres are rounded to the nearest multiple of 5 for presentation purposes, then they probably are the same height. -Ian Quote Link to comment Share on other sites More sharing options...
Alex Posted September 5, 2002 Share Posted September 5, 2002 If the Z rated tyres arn't as good as Y rated ones...why fit Z rated ones to the Mac F1??? Bench rests Quote Link to comment Share on other sites More sharing options...
randy Posted September 6, 2002 Share Posted September 6, 2002 If that is so this is how it should appear!! P225/50ZR16 149mph+ 240kmph+ P225/50ZR16 91W---- 168mph---- 270kmph P225/50ZR16 91Y 186 mph---300kmph The Z stays where it is like the example on top but they are rated seperately on the sidewall next to the load index--W-Y etc.. Below is the tire side wall info!! Quote Link to comment Share on other sites More sharing options...
Syed Shah Posted September 6, 2002 Share Posted September 6, 2002 A Z rated tire is rated for speeds for 149mph. How much over? Well obviously more than 186mph, otherwise Mclaren would not have fitted them like Alex said. Quote Link to comment Share on other sites More sharing options...
randy Posted September 6, 2002 Share Posted September 6, 2002 If you read the above thread and my previous thread you would have understood better! Z is an old speed rating that is still used today to identify High Performance tires. The new rating is W and Y-- MAX PERFORMANCE TIRE where they have been specifically and reliably tested to the speed they mentioned 168 and 186. The Z as they have mentioned has been tested upto only 149mph the old performance rating which is specific to most brands. Although Mc Laren may have used the Z rated tires they were made specifically for Mc Laren by Goodyear the Eagle F1/Supercar tires as original equipment in 1995. These tires in specific were tested by Goodyear for speed. They were special tires which had very large tread blocks formed into asymmetric and directional tread designs. Since each of these vehicles uses different front and rear tire sizes, they all require four separate “corner specific” tires to give the required performance. Hope you got this!! Quote Link to comment Share on other sites More sharing options...
Mark Kindell Posted September 6, 2002 Share Posted September 6, 2002 Just a note but these speed ratings ar meant as a guide for SUSTAINED high speed runs and how offten do we get to keep up those sort of speeds on U.K. roads The speed rating is worked out by how well the tyre disapates heat along with other things ! thus a car thats heavy may want to use a tyre with a higher speed rating ! Quote Link to comment Share on other sites More sharing options...
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