How Much Does Tire Profile/Rim Size Effect Ride?
#16
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#17
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Originally Posted by Koma
Don't forget about runflats. I've heard those don't dampen very well.
Don't forget about runflats. I've heard those don't dampen very well.
Run-flat tires, of course, have to support the weight of the entire car and the load in it, with no air at all, for up to 50 miles at 50 MPH ( generally their recommended limits ). That requires an extremely strong sidewall made out of durable materials. Those materials just don't give much when you hit a bump......air or no air. It is just one of the concessions, along with their relatively high cost and limited availability, that you have to make when you choose them. They also sometimes don't wear very well ( like on the run-flat Toyota Sienna ), because the super-hard sidewalls don't always allow the surface tread to flex while cornering to stay even with the road surface, so you end up wearing out the outside edges. This problem, though, to an extent, has been dealt in the latest run-flat Corvettes by suspension changes.
Last edited by mmarshall; 03-15-07 at 04:11 PM.
#18
Lexus Fanatic
The Aveo is not a domestic, except for the Chevy nameplate. It is a Korean Daewoo subcompact built in Korean plants for Chevy. See my description of the car in an earlier post.
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I saw that lengthy excerpt I was just making a general reference to the name plate. Much in the same vein as the GTO not being a domestic either.
#20
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Yes, my new MX-5 has the option of run flats (because it has NO spare either way!) but I had NO interest. (And since it has no spare it comes with a mini sealing slime bottle / inflator kit in the trunk )
#21
I got rid of my GS400 last weekend because I'm going to be getting a new Corvette. The paperwork is still being filled out right now so I probably wont' be able to pick up the car for another few days. While I'm waiting I rented a Chevy Aveo because I blew all my money on the Vette and I didn't have any extra to spend on a rental
The Aveo is a complete piece of crap, probably one of the worst cars I've ever driven. The interior is trash, it's probably the ugliest car on the road, and I'm almost embarrassed to be seen in it. One thing that absolutely shocked me though is the quality of the ride. This might be almost blasphemous to say on here, but the car rides better than my GS ever did. Driving it over the same terribly maintained Boston streets, it goes over potholes, bumps and road imperfections a lot more smoothly than the GS. I almost couldn't believe it
The only explanation I have is that the Aveo is riding on 14 inch (maybe even 13?) rims with high profile tires. My GS (suspension and rims remained stock) had 245/45/ZR17 low profile Kumho Escta ASX tires. Thinking about all the cars I've ever driven, it seems like the ride quality is directly proportional to the profile of the tires. Nothing else really seems to matter. Obviously the GS weighs about 1000-1200lbs more than the Aveo, and handles exponentially better (although the Aveo can be manhandled through turns pretty well) so the suspension probably has to be stiffer in order to deal with the weight and deliver the performance required, but there is still no reason a *****box rental like the Aveo should be more comfortable than a Lexus that costs about 5 times as much when new.
Maybe I'm just hallucinating, but has anybody else ever experienced something similar?
The Aveo is a complete piece of crap, probably one of the worst cars I've ever driven. The interior is trash, it's probably the ugliest car on the road, and I'm almost embarrassed to be seen in it. One thing that absolutely shocked me though is the quality of the ride. This might be almost blasphemous to say on here, but the car rides better than my GS ever did. Driving it over the same terribly maintained Boston streets, it goes over potholes, bumps and road imperfections a lot more smoothly than the GS. I almost couldn't believe it
The only explanation I have is that the Aveo is riding on 14 inch (maybe even 13?) rims with high profile tires. My GS (suspension and rims remained stock) had 245/45/ZR17 low profile Kumho Escta ASX tires. Thinking about all the cars I've ever driven, it seems like the ride quality is directly proportional to the profile of the tires. Nothing else really seems to matter. Obviously the GS weighs about 1000-1200lbs more than the Aveo, and handles exponentially better (although the Aveo can be manhandled through turns pretty well) so the suspension probably has to be stiffer in order to deal with the weight and deliver the performance required, but there is still no reason a *****box rental like the Aveo should be more comfortable than a Lexus that costs about 5 times as much when new.
Maybe I'm just hallucinating, but has anybody else ever experienced something similar?
Low-pro tires will not have a major impact til you start running below 40series and running wider rims causing car to want to follow grooves in the road. Impact from broken pavements are felt much more clearer. Other than that, low-pro are actually better when combined with a firmer suspension. They ride more stable, offers more grip, sharper and quicker steering response, less slack overall. Since there is practically no give to them, they allow your suspension to work to it's full potential, you just have to do what us Ricers do and constantly avoid manholes and slow down when entering drive ways and speed bumps to avoid bending your nice rims.
Over inflated hi-profile tires will make car ride worse than properly inflated low-pro wheel/tire IMO.
#22
Lexus Fanatic
Low-pro tires will not have a major impact til you start running below 40series and running wider rims causing car to want to follow grooves in the road. Impact from broken pavements are felt much more clearer. Other than that, low-pro are actually better when combined with a firmer suspension. They ride more stable, offers more grip, sharper and quicker steering response, less slack overall. Since there is practically no give to them, they allow your suspension to work to it's full potential, you just have to do what us Ricers do and constantly avoid manholes and slow down when entering drive ways and speed bumps to avoid bending your nice rims.
Over inflated hi-profile tires will make car ride worse than properly inflated low-pro wheel/tire IMO.
Over inflated hi-profile tires will make car ride worse than properly inflated low-pro wheel/tire IMO.
I general, Mercedes and BMW have come closest to achieving the best and most ideal compromises in combining both ride and handling with a conventional suspension....and BMW clearly leads the industry in the design of their power steering and road feel.
Yet, even with a computer-controlled suspension, you cannot have firmness and softness combined AT THE SAME TIME....once again, the old ride vs. handling law kicks in. The shocks will stay soft when you are driving straight and level, but firm up in sharp turns to control body roll, so you get a relatively soft ride in easy driving and more firmness while agressively cornering....you can't have both at once.
This also works, in general, for tires as well. While many factors are involved.....things like rubber compound, air pressure, suspension design, etc.....in general, a lower profile gives better handling at the expense of ride; a higher-profile better ride at the expense of handling. You can't have both ride and handling at the same time. It is simply one of the laws of physics that engineers have to deal with when they design a vehicle....and as I stated previously, Mercedes-Benz engineers have probably mastered the suspension compromises needed better than any other auto company; BMW for steering.
Last edited by mmarshall; 03-16-07 at 10:16 AM.
#23
Nicely said mmarshall. But I think it's more a personal taste than anything. Which is why Camry outsells all cars despite losing all car magazine shootouts. I personally don't care for BMW or Mercedes suspension tunning. Mercs are all around too soft, and BMW too rough yet too much roll for daily driving. Both have numb and slow steering IMO.
#24
Nicely said mmarshall. But I think it's more a personal taste than anything. Which is why Camry outsells all cars despite losing all car magazine shootouts. I personally don't care for BMW or Mercedes suspension tunning. Mercs are all around too soft, and BMW too rough yet too much roll for daily driving. Both have numb and slow steering IMO.
#25
Lexus Fanatic
Nicely said mmarshall. But I think it's more a personal taste than anything. Which is why Camry outsells all cars despite losing all car magazine shootouts. I personally don't care for BMW or Mercedes suspension tunning. Mercs are all around too soft, and BMW too rough yet too much roll for daily driving. Both have numb and slow steering IMO.
You are correct, though, that much of the Camry's popularity comes from its luxury car-like ride softness and noise isolation at a family-sedan price. Many people, especially as they age, prefer comfort over handling.
Last edited by mmarshall; 03-16-07 at 04:12 PM.
#27
There are alot of other stock cars that offers superior driving dynamics to any BMW. If vehicles built for track purposes were my background, then I would say many exotics will also feel numb and slow.
A Camry or sportscar doesn't try to be anything else. Both know exactly what they were design for. A BMW is like hot chick shopping at the mall.
Last edited by RiceMaster; 03-16-07 at 12:10 PM.
#29
Out of Warranty
I think the consensus here is that basically every car is a compromise. If you want sharp handling, you are going to sacrifice some degree of comfort, quiet, or appearance. An F1 car has fairly narrow sidewalls, but they are not extreme. That sidewall has to flex sufficiently under side loading to keep the contact patch flat on the track, but not so much as to make the handling squirmy. A wide tire with a very thin sidewall may be stylish, but it is not an optimal handler, given a streetable suspension, and it's going to deliver a pretty solid THWACK!! with every tar strip it encounters.
I remember taking the skinny OEM Goodyears off my new '67 Mustang after only a couple thousand miles (and one hundred-mile run through the Arizona desert at over 110 (degrees and mph) - the fabric of all four tires had separated from the rubber and the tires couldn't hold air for more than 30 minutes. I learned about racing a carload of pretty ladies in a similar car (Cougar) from that.
I put on a set of the then-new Firestone "Wide Oval" tires that were every muscle-car owner's dream. They stuck, they handled pretty well, but they were extremely heavy and flexed not at all. They were rough as a dried cob but they put a HUGE (for 1967) contact patch on the ground, with a 2-ply polyester carcass and 2 fiberglass bias belts, they were high style, but delivered a pretty miserable ride. They wore out in about 18K, thanks to that soft but grippy compound. Ah well, there for about six months, I was stylin'!
I remember taking the skinny OEM Goodyears off my new '67 Mustang after only a couple thousand miles (and one hundred-mile run through the Arizona desert at over 110 (degrees and mph) - the fabric of all four tires had separated from the rubber and the tires couldn't hold air for more than 30 minutes. I learned about racing a carload of pretty ladies in a similar car (Cougar) from that.
I put on a set of the then-new Firestone "Wide Oval" tires that were every muscle-car owner's dream. They stuck, they handled pretty well, but they were extremely heavy and flexed not at all. They were rough as a dried cob but they put a HUGE (for 1967) contact patch on the ground, with a 2-ply polyester carcass and 2 fiberglass bias belts, they were high style, but delivered a pretty miserable ride. They wore out in about 18K, thanks to that soft but grippy compound. Ah well, there for about six months, I was stylin'!
#30
Lexus Fanatic
I put on a set of the then-new Firestone "Wide Oval" tires that were every muscle-car owner's dream. They stuck, they handled pretty well, but they were extremely heavy and flexed not at all. They were rough as a dried cob but they put a HUGE (for 1967) contact patch on the ground, with a 2-ply polyester carcass and 2 fiberglass bias belts, they were high style, but delivered a pretty miserable ride. They wore out in about 18K, thanks to that soft but grippy compound. Ah well, there for about six months, I was stylin'!
Yeah....I remember the Wide Ovals, too.....and the old TV ads for them.
But.......welcome to the 21st Century. Today's ultra-low-profile high-performance tires do much the same thing as the old Wide Ovals did 40 years ago....cost too much, wear out quickly, give a lousy ride, slide all over the place on slippery roads, and offer little impact protection.