Quote:
Originally Posted by tlr3715
I wanted to start a discussion about tire width, because I think it's a terrible trend that no one it talking about.
Basically my feeling is that in the name of penny pinching most car manufacturers (GM included) have under tired their cars as time has gone by. Horsepower has gone up substantially while tire width remains the same or has even decreased. Instead relying on stability and traction control electronics to keep the vehicles under control by utilizing the new electronic throttles to strangle the engines. I have felt for a while that many of us are paying for engine HP when, in reality, only a fraction of the power is available to us unless we are already moving quite quickly.
Brief history of my own car experience and the ratio of drive wheel tire to HP:
1999 Firebird Formula - 300 HP, 245 width tires - .817/HP
2002 Camaro Z28 - 305 HP, 245 width tires - .803/HP
2005 350Z Roadster - 276 HP, 245 width tires - .888/HP
2006 Corvette - 400 HP, 285 width tires - .713/HP
2012 370Z Nismo - 350 HP, 285 width tires - .814/HP
With all of these cars, as long as I was moving I could stomp on the gas on any dry road with TCS off, get immediate hook and take off. It is a magical feeling. The firebird didn't even have traction control and I never felt unsafe in it.
Let's look at some other classics that I have not had the pleasure of driving just for reference:
2002 Corvette - 350 HP, 275 width tires - .787/HP
2002 Viper - 450 HP, 335 width tires - .744/HP
1996 Supra - 320 HP, 255 width tires - .797/HP
Now lets compare that to some modern cars:
2017 Mustang GT performance package - 435 HP, 275 width tires - .632/HP
2023 Camaro SS - 455 HP, 275 width tires - .604/HP
2023 Corvette Stingray - 490 HP, 305 width tires - .622/HP
2023 Challenger R/T Scat Pack Widebody - 485 HP, 305 width tires - .629/HP
Quite simply tire width is not keeping up with engine power advancement. Sure tire tech has improved and you can get more grip out of the same width of tire than you could in the early 2000's, but the ratios are not even close to what they used to be.
I chose the 2017 Mustang as one of the ones to compare, because that was my last car. My experience with it was that I was only able to get the pedal to the floor in first gear if it was a dry day in 80+ degree weather. Most of the time I was lucky to get 2/3 throttle before the tires would break free or start hopping. Could rarely get the same rush of acceleration as my 2006 corvette even though the mustang had more power. Same experience when I test drove a Challenger SRT a few years ago. I have not been able to test drive an SS as there are none around here, but would imagine the experience would be the same, its too much power on a narrow tire, and I think GM has designed the stability and traction systems to create the illusion that we are getting close to full power when we step on the gas when reality might be quite different.
When I drove the older cars gas pedals were directly connected to the engines. I was in control of how much gas that engine got at all times. In fact the traction control on the Camaro operated by physically forcing your gas pedal up as it was the only way to prevent throttle. With the current electronic throttles, I never know what is actually getting to the engine. I think that realization today gave me pause.
Don't know if there is a point to this rant, but as I look to buy a new Camaro (after looking at all current options I think it's still the best for my needs) I realized that those days are over and we have lost a really great experience and connection to the engines we love plus the ability to get the power to the ground in really fun ways that I think has just faded away over time without too much notice. It's a shame, and felt I had to share this thought with some people who may also "get it".
|
Hello, your observation of a decreasing ratio between tire width and engine maximum horsepower from late 1990s to nowadays are valid. But it is not sufficient to justify your point.
A better way to describe whether car manufacturers have mistakenly undersized the tire on the ever more powerful sports cars would be the ratio: (maximum horsepower/maximum friction force can give by tires). With just the ratio you proposed (tire width/horsepower), it is insufficient to evaluate whether the tire width is capable for a given horsepower, because apparently modern tires are more grippy (i.e. provide higher friction force with the same area under the same downward pressure) thanks to the advancement in chemistry. Not to mention the stability control and other performance technologies have improved a lot on modern sports cars.
For your reference, gen6 Camaro ZL1 1LE (lap time: 2:45.0), Camaro SS 1LE (2:54.8) are faster on the same track with ever more impressive lap time comparing to those sports cars in the 1990s and early 2000s.To clarify, the lap times are nicely complied by Car and Driver:
https://www.caranddriver.com/feature...storical-data/. Yet, you will find Camaro ZL1 1LE and Camaro SS1LE did poorly for the ratio of tire width/horsepower, ZL1 1LE is about 0.5 (325mm/650hp) and Camaro SS 1LE is 0.68 (305mm/450hp). Would you say Chevy “underwheeled” these 2 cars because they are so low on the width/horsepower ratio? If ZL1 1LE is more slippery than SS 1LE due to a lower ratio of tire width/horsepower, how did ZL1 1LE finish the track quicker than SS1LE?
Another piece of data would be, the lap time for the gen5 Camaro SS 1LE (2:54.8) is almost as good as 2009 Chevrolet Corvette ZR1(2:51.8). I can say 2009 Chevrolet Corvette ZR1(over 600hp) has a wider tire (335mm) and way more horsepower than Camaro SS1LE but failed to do proportionally better.
With these data above, maybe I can say a lower width/horsepower ratio marks the advancement in modern day sports car technology. There will always be a trade off between weight, rolling friction, maximum grip and faster lap time.