I recently bought a 2001 coupe with Z51 and the 6-speed. It has 15,000 miles and is riding on its original Goodyear Eagle F1 EMT tires. They are starting to crack, so I have a tire decision to make. I am concerned about differences in handling and want to know what people have experienced going from run flats to non-run flats and vice versa.

I am concerned that with a softer sidewall it will have less ultimate grip in corners because the sidewall is tucking under more, causing the car to lean more, which throws the weight of the car more to the side. In theory, that can cause it to lose traction sooner.

Second, Tire Rack has told me the steering response will generally be slower with a softer sidewall. I don't think I'd like that.

One possible handling benefit there may be with a softer sidewall is that a harder sidewall tire can tend to cause the car to bounce around on bumpy curves, which will cause a loss of traction. I guess it would depend on just how stiff the sidewall is with a run-flat.

I would like to know people's experiences going from run flats to non-run flats, and vice versa. Keep in mind that if you've gone from a worn out tire to a new one, the handling may well feel better simply because you have a new tire. Try to take that in to consideration when you relate your experience.

When you describe your experiences, please give me details. Simply saying, "It handles better" doesn't help me. How does it handle better? Does it have more grip in turns? Is the steering response faster? Etc.

I know about the differences in ride and noise. I've read dozens of posts on this website so comments about softness of ride and the noise level are of no benefit to me. I've also read dozens of posts about getting a flat or having a blowout. Please don't leave comments about that issue because I've already thought it through. Ditto with the price difference. What I'm most concerned about is the handling issue, namely, what have been people's actual experiences.

-Jim

 

You certainly are not going to loose performance by going non runflat. There are many stiff sidewall nonrunflats available. If you want some great street tires, take a look at the Nitto NT05. Each brand will offer a serious performer like this one. You wont be sacrificing anything.

 

If you elect to go non-runflat, it is simple to get an emergency can to fill up the tire similar to what GM put in the C5 Z06 cars. From a handling point of view the non-runflat tire should greatly improve your handling imputs, stopping ability, smoother ride quality and will grip the road better. Your major tire manufactures make several types of tires from runflats to all season to extreme summer handling. Since I only drive my Corvette in the warmer weather and I like to autocross, I have extreme performance tires with a 200 rating and they are 3-4 seconds faster than my runflats on a 45 second course. Occasionally I will go on a long trip and I put the runflats on because they get better gas mileage and they need to be exercised or they will dry out. My runflats are original--2000--and only have about 14000 miles on them and, like yours will need to be replaced soon.

 

I changed from runflats that came with the car to PS 2's and the difference in handling, ride and the reduction road noise was amazing. It became a different car. I'll never buy runflats.

 

what do ya do? carry a plug kit?

 

You mean sort of like how Ferraris, Lamborghinis, Lotus, Porsches, and many other premium sports cars handle badly and have slow steering response due to not running runflats.............??. Damn, if only they knew how wonderful runflat tires are............NOT!!!

Do yourself a favour, if you're serious about improving every single aspect of your ride and handling, get rid of your runflats and don't ever look back. Forget they even exist! If some tire vendor tells you it might adversely affect some handling characteristic of your car, go elsewhere. It's as simple as that. There are no benefits whatsoever with runflat tires. None.

 

Run-flat = garbage. There is no argument for them.

 

You mention a difference in handling. In what way was it different? More grip in turns? Less bounce over bumps in turns, resulting in better control? More steering feel? Less steering effort? Quicker steering response?

 

For me with the NT05s, and for most anyone switching to nonrunflats, the difference in handling is night and day. The ride is smoother and more comfortable, there is less bounce due to softer compound, much more confidence on the corners. No squeal where I was able to squeal the stock runflats. When the car was stock and the tires were the first thing I changed, I went from being able to spin the tires punching it at a red light, to the car hooking right away and maybe giving a chirp, sometimes not even that. I remember being thoroughly impressed by the ability to punch it and make full use of the factory power off the line. Steering effort remains the same. Just a much better ride, and incredible confidence around corners. I have taken some corners so fast I know the runflats would have gave out from the way they felt before. I have never even got the NT05s to squeal around a corner! Im afraid to push it that far. Ive already gave myself some scares!

 

Thanks. This is very helpful. What brand are NT05's?

 

Did you notice a difference in gas mileage?

 

Remember that the original run-flats are using almost 20 year-old technology. If you want to stay with run-flats, you can get a much better tire that will give you everything you want than those old Goodyears. Good luck.

 

Nitto is the brand. Their website has good info. I use them as my street tires. Love them. I use the street NT05, not the competition NT05r. The NT555 is also a popular choice. But Im all about the performance.

 

In short, yes

I did a few things for fuel economy right off the bat when I got the car. Three big things included a K&N intake, Bassani axlback and x-pipe, and the NT05 non-runflat tires. Weight reduction and minor things like a self p&p of the TB and NGK sparkplugs, fuel filter replacement, O2 sensor replacements, etc. all allowed me to get a fresh start and 31-32 mpg on highway which is a lot higher than an auto is rated for. I feel that the three modifications played a part in getting me there.

Also, I run the NT05s in sizes 245/40 17, and 285/35 18. Be aware that this is a slightly smaller diameter than OEM size, but has slightly wider tread. I think on top of the loss of run-flats, maybe less diameter plays a small role in the better fuel economy too.