Originally Posted by JR OTR

To make the comparisons even fairer, we would have to prove that you ran 420k miles on 8 retreaded duals for three sets in a row, something I'm sure you can back up with real hard numbers. Now, I'm not calling BS, mind you, but perhaps some other drivers with similarly durable recaps could show up and back up that data point.

Also, I claimed the $11,000 estimated savings over four years ("I'm just past the third complete year in my lease with super singles and I estimate that by the end of this year").

The numbers I used to come up with my estimate were a 5% fuel savings on fuel (works out to .3 MPG assuming base is 6.0 MPG), a $1,500 cost of changing from factory tread and rims to wide base (my actual cost in 2008), and 300,000 mile intervals on the tires themselves. I used my actual fuel expense for my first three years of operation as the baseline for fuel, realizing that as time goes on the price of fuel will tend to rise and thus the margin between duals and wide base tires moves more and more towards the wide base side.

I'll admit, since I wouldn't consider using recaps for drives I had not considered someone going that route so your per-tire cost would be lower. Assuming your out-of-pocket cost for a full set of such tires would be on the order of $1,800 or so with the dismounting, mounting, balancing and the like the difference would be roughly $8,500 in favor of wide base, again according to the numbers I supply above. If you expect to receive 420k miles of service from your recaps this would save you one set of tires in about 1.26 million miles vs changing out fresh wide base rubber every 300k, for a savings of $1,800, bringing the difference to roughly $6,300.

As far as fuel savings vs relative rolling resistance, according to Michelin you're a lot further away than a tenth of a MPG with the tires you mention... according to their own data on their own site.

Good luck,

Jim

Originally Posted by Orangetxguy

I really gotta wonder about those......"Executive" decisions to use recaps on super singles.

Originally Posted by JR OTR

On the chart provided the higher numbers are better... note in the description: "For reasons of simplicity and consistency we have opted to reflect rolling resistance by a relative index."

Originally Posted by no_worries

I'm afraid you don't know what you're talking about...

Originally Posted by Copperhead

Well, Jim was right that I was talking about caps on duals. As for the choice because of being a "penny pincher", well I have NEVER thrown a cap in 20 years of using them from the Rio Grande to Yukon Teritory. And is it ok to just spend more because you can write it off on the taxes? Not sure how spending a dollar to save 20 cents in tax is a sound judgement call.

Now back to Jim. I have no doubt you did save money running the SS. But my original point was that compared to a low rolling resistance dual type tire, the difference is not so noticeable. My year round average mpg, with an average 35k plus in the box, counting all idle time (no APU) is around 7.5 mpg. Higher in summer, lower in winter. The retreads I just put on last week were low rolling resistance Michelin XDA2 23 AT. ECM from last week was 8.4 mpg and this week 8.3. Hand calculated, actually came in at 7.8 since I put on the new caps. The problem with stating a definitive mpg increase with SS over a good dual tire, is that once you get into higher mpg territory, any real mpg gains get smaller and smaller. If someone is getting 5 mpg, just about anything new will show a mpg improvement. Once you get near 8 mpg, any mpg gains by changing something gets very small. That is why I disputed a blanket claim that just going to a SS will virtually net a .5 mpg increase. For that 5 mpg truck, it just might. For my setup, highly doubtful, though it might pull off a tenth. In which case, the ROI by doing a complete changeover to SS would be a very long time if ever fully realized.