Classiccars2

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 curious to know what peoples' experiences have been in terms of gas mileage when going from a run flat to a non-run flat and vice versa.

In theory, the non-run flat, with its softer sidewall, will have more give, and that could result in great fuel consumption. So I want to know peoples' actual experiences.

Please don't tell me that with a car like this I shouldn't be concerned about gas mileage. It's my money and I can manage it how I like. Also, I've read dozens and dozens of posts on this website about run-flat versus non-run flat and have sorted through the issues of ride, noise, the price differential, and getting a flat. So please don't tell me about those issues. In a separate post I have left I have raised the issue of handling differences.

If by chance you drag race your car your experiences may be of value to me with respect to gas mileage. In theory, the non-run flat, with its softer sidewall, will have more give and that could result in poorer performance at the drag strip. I'm not concerned about drag racing, but if a non-run flat has that kind of affect on the performance in a drag race it probably has a similar affect upon the gas mileage.

Another factor to consider also when thinking about the difference in gas mileage between the run flat and non-run flat is the softness of the compound. If it was significantly different between the two tires that could effect gas mileage and the difference experienced in gas mileage between the run flat and the non-run flat may have been due to that, rather than RF vs. NRF.

-Jim

Evil-Twin

better fuel economy with run flats, slightly. The difference is hardly measurable. the amount of air in the tire has more effect on fuel economy. Run flats and 60 Ft times at the track show significant poor performance. Run flats are for convenience and peace of mind, especially for older consumers. Everything is a trade off, Give up the convenience and peace of mind, and you can get a much better performer, with much less noise, and better handling. Run flat tires are heavier so this is a negative in mpg, but the overall tire might give you an extra 1 to 2 mpg. If you weigh pro's and cons of either run flat or non run flat, the better fuel economy is way down the list of benefits.

chaase

I doubt you even get better MPG if the non run flats are inflated properly. The extra weight of the run flat tires counts as unsprung weight. Consider that the Z06 and non z06s get the same fuel economy and the Z06 has worse aero, more hp, non run flat tires and a tighter gear ratio. The only benefit is that the Z06 is lighter.

Quicksilver Vert 01

I think you may be a little generous with that 1 to 2 MPG increase run flats might give.

I made the switch from run flats to conventional tires on my '01, about four years ago, and did not see a measurable change in gas mileage after the switch.

What I did see though, was a much smoother and quieter ride, and better overall steering response and road feel, with the conventional tires.

QCVette

Although as Quicksilver Vert 01 stated "I think you may be a little generous with that 1 to 2 MPG increase run flats might give."

I have even heard that the runflats can add 3 to 4 mpgs, but when I changed from runflats there was no noticeable change in mpg.

NukeC5

3 to 4? no way in hell. 1 to 2? I dont even believe that. Take the same dimension tires in both run and non runflats and air them properly. The lighter of the two will yield better fuel economy. And probably in the .5 per gallon range. Nothing noticeable. Dont change tires for fuel economy. Do it for performance.

lionelhutz

Ummm, anything technical you post here is subject to criticism and people are very justified to post that their real world experience with a C5 says that 1-2mph between run flats and non-run flats is wrong. I've run both the stock wagon wheels and stock sized run flat rubber and my 19" CCW's which are both wider and non run flats and didn't notice any difference which means it was well below 1mpg.

QCVette

Disregard this post. It was a response to a posting that was deleted and no longer in this thread.



I am not sure if you are intending this blast for me, but I agreed with you. You wrote a paragraph with the same points that I would have made too.

My additional comments were my experience with what I had heard and what I experienced when I changed from runflats.

I hoped the OP could follow your points and my comments about my experience.

Classiccars2

Quicksilver, your response is one of the most informative I've gotten (I also posted a message about the handling differences).

So what non-run flat did you buy?

Quicksilver Vert 01

Kuhmo Ecsta SPT at www.tirerack.com

Check out the reviews and decide for yourself.