tires
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Grant@tirerack
- Posts: 722
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If you plan on doing any driving even in light snow, the Dunlop, Yokohama, and Either Michelin would be far safer than the Firehawks. The SZ50 is a nice tire for wet and dry use but is worthless in even light snow or ice. You might as well park the car and get out the Pathfinder 
The internal ply/belt construction on the symmtrical and asymmetrical tires are the same, only the tread design is changed. They went with the wider sweeping rain tread design on the wider, lower profile sizes. It's not one of the more aggressive handling tires but does very well for an all-season. Much better wet traction (in both tread designs) than the Yokohama AVS DB 2. This is mostly due to the redesigned tread blocks on the shoulder of the Yokohama. The outer blocks are tied toghether to reduce heel-toe wear that plagued the first version. The trade-off is reduced wet traction as the tire wears. The XGT V4 would be the better of the Michelins. The H4 would be too soft for my tastes on that heavy of a car. The other issue is Michelin's use of half depth sipes (the narrow slits in the shoulder tread blocks). They do this to maintain better wear on the outer edges of the tread. The only problem is that once you get about half way into the tire wear half of the outer slits disappear. While this is great for dry traction, it increases the tendency of the tire to loose grip on wet pavement in corners. Tire design is always a give and take and each manufactuer has their own way of attacking a problem. There will always be trade offs I guess. :rolleyes
The internal ply/belt construction on the symmtrical and asymmetrical tires are the same, only the tread design is changed. They went with the wider sweeping rain tread design on the wider, lower profile sizes. It's not one of the more aggressive handling tires but does very well for an all-season. Much better wet traction (in both tread designs) than the Yokohama AVS DB 2. This is mostly due to the redesigned tread blocks on the shoulder of the Yokohama. The outer blocks are tied toghether to reduce heel-toe wear that plagued the first version. The trade-off is reduced wet traction as the tire wears. The XGT V4 would be the better of the Michelins. The H4 would be too soft for my tastes on that heavy of a car. The other issue is Michelin's use of half depth sipes (the narrow slits in the shoulder tread blocks). They do this to maintain better wear on the outer edges of the tread. The only problem is that once you get about half way into the tire wear half of the outer slits disappear. While this is great for dry traction, it increases the tendency of the tire to loose grip on wet pavement in corners. Tire design is always a give and take and each manufactuer has their own way of attacking a problem. There will always be trade offs I guess. :rolleyes-
Q45tech
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- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Aren't most tires pretty well done when half worn away? Either the durometer hardness of the compound gets severe or the internal stresses have broken so many filaments or the tricks [sipes] used are worn.Most tire engineers I speak to, say 20,000 miles is the limit for most designs regardless of their promises......depending on vehicle weight.The problem I has with the 5000 was the mushy sidewall at anything less than 50 psi with the Q front weight load but going straight they were decent.
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Grant@tirerack
- Posts: 722
- Joined: Thu Jul 17, 2003 9:17 am
- Car: Auto racing (AMLS, Cart,F1,IRL in that order), old show rods, classic monster and bad sci-fi movies,
- Contact:
That is true, most tires loose both dry and wet grip beyond the halfway point. The main reason is the change in compound as they age. Oils tend to migrate out of the compounds (which is why tires tend to turn brown as they age), and the constant heating and cooling of normal driving will continue to speed up the process. Some tire makers are starting to use dual layer compounds to make the tires more consistant. They are also using additives (resins) to the compounds to resist the migration of oils in the compound. These are advances in compounds but they can only go so far. The internal construction of tires also will break down as the tire is used/abused. Runing an overloaded tire for even a short period of time will damage the internals of any tire. That is why is it critical to run adequate air pressures. The minimum listed by Infiniti on this car is exactly that, minimum.
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Grant@tirerack
- Posts: 722
- Joined: Thu Jul 17, 2003 9:17 am
- Car: Auto racing (AMLS, Cart,F1,IRL in that order), old show rods, classic monster and bad sci-fi movies,
- Contact:
coffee... coffee.... :sleep I can't type worth a darn before the sun is up. I try to keep it simple when ever possible but sometimes with tires that's is hard to do. There's just so much going on there. If one thinks about it, tires are amazing things. It's sorta like a Mr. Wizzard show under your car! It gets very trying for my wife to listen to me go on about it. Maybe it's a good thing we have an outlet here :bearchug
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Anybody in Akron, Ohio.........the Tire Society Annual Symposium starts tomorrow.............two days of exciting cutting edge PHD read topics with slides and videos.
"the effects of [tire] block size on friction in a lateral slide in wet conditions".......maybe........use of animal by products as fillers in premium tires made in India........gerbles/rat claws in specialty ice tires..............who knows what might be proposed or discussed.At least there won't be pickets now that Gyear has settled.
Watch out driving around town late at night you might hit a conventioneer and there would be 12 experts on hand to prove your tires were at fault.
"the effects of [tire] block size on friction in a lateral slide in wet conditions".......maybe........use of animal by products as fillers in premium tires made in India........gerbles/rat claws in specialty ice tires..............who knows what might be proposed or discussed.At least there won't be pickets now that Gyear has settled.
Watch out driving around town late at night you might hit a conventioneer and there would be 12 experts on hand to prove your tires were at fault.
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Grant@tirerack
- Posts: 722
- Joined: Thu Jul 17, 2003 9:17 am
- Car: Auto racing (AMLS, Cart,F1,IRL in that order), old show rods, classic monster and bad sci-fi movies,
- Contact:
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szh
- Posts: 15932
- Joined: Tue Jul 23, 2002 12:54 pm
- Car: 2018 Tesla Model 3.
Unfortunately, no longer a Nissan or Infiniti, but continuing here at NICO! - Location: San Jose, CA
[quote=" Q45tech I keep hoping someone will read these sites [/quote]
I worked my way through a few of the above. Very interesting indeed! It is always interesting to see how technical fields get ... the average layman does not stand a chance to get things right! Technical papers in my own field tend to be pretty heavy slogging, and it is pretty darn clear (and slightly discouraging) that something as commonplace as tires can have such advanced technology issues that it is difficult to understand them thoroughly.
Z
I worked my way through a few of the above. Very interesting indeed! It is always interesting to see how technical fields get ... the average layman does not stand a chance to get things right! Technical papers in my own field tend to be pretty heavy slogging, and it is pretty darn clear (and slightly discouraging) that something as commonplace as tires can have such advanced technology issues that it is difficult to understand them thoroughly.
Z