Hi.......... Check out: The Prancing Horse - Number 154 - First Quarter 2005 The Quarterly Magazine of the Ferrari Club of America [FCA] An article entitled "Replacement Tires for Ferraris" appears on pages 40 through 42 of this issue of the magazine. The author, Bill Badurski, is a former 365 Boxer owner and an owner of several Daytonas with years of experience as the Technical Chairman of the FCA. In the article, Badurski describes all of the relevant parameters of tires and discusses the replacement of Michelin XWX 215/70-15 tires on a 7.5-inch rim in the summary. The only fact which he fails to mention in the search for replacement tires is an obscure one. The old V speed rating is the current H rating of 130 miles per hour, according to information provided at the Tire Rack Website, as of 1991. Good luck !!! Frank.........23005 www.masiarz.net/bb_resource
Beg to differ...The 'old' V-speed rating on the XWX series corresponds to speeds of more than 240km/h or circa 150mph. Those days there are not many cars that can hit speeds of 150mph and the speed ratings are based on the ability to sustain said ratings, i.e S, H and V for the duration of TWO hours.. Suffice to say, I don't think anyone would run Daytonas,Boxers or Countaches for two hours on end except on the track...and for that these cars are normally shod in so-called race tyres. For all intents and purposes the other important aspect is the load rating, i.e the script after the sizes and profile..eg : 215/70/15 (93V) The 93V is the load index. It can be different among manufacturers due to the nature of construction, the rubber compound etc..but in most cases they are similar. That is important because the heavier cars will make more heat during high speed driving and the load imposed on the tyres will be more substantial.. JMO
Hi......... Bottom line: consider a 235/60-15 tire as a replacement for a 215/70-15 Michelin XWX tire. 1977 BB512 S/N 23005 rides on 235/60-15 and 255/60-15 Michelin Sport XGT tires now, with no wheel well clearance problems, given proper shock absorber performance. A 235 tire at both ends of a Boxer should work well, as the 255 XGT tire is "out of production"....one of the saddest phrases in the English language. Good luck !!! Frank.................23005 www.masiarz.net/bb_resource
Hi again......... Check out: http://www.tirerack.com/tires/tiretech/general/ownersmanual.jsp and search for articles on age limitations and other topics of interest. Check out: http://www.tirerack.com/tires/tiretech/general/speed.jsp for discussion of tire speed ratings. Nothing is simple !!! Frank..............23005 www.masiarz.net/bb_resource
Hi........ Very late response, but agree with you !! See the TireRack article: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35 Hard to imagine that "in excess of 130 mph" includes 175 mph performance too. Tire selection for older high performance vehicles is a difficult operation, unless one upgrades to larger wheels. One really needs W- or Y-rated tires to safely support "sustained" high speeds for any exotic older vehicle....Boxers, Daytonas, Miuras and Countachs. Indeed, load rating is extremely important as well. See tires "specs" at the Tire Rack site. Load ratings vary with size and speed rating specifications. Remember, the Boxer is a heavy vehicle. Frank......... www.masiarz.net/bb_resource
