OK, this one can be fun. Lots of ways to look at this.
MN Flyer, I think that using a five tire rotation would give you 20% longer life for the set. Operative word is “set”.
There are assumptions that you could put in, but no reason to make this too complex. At the end of the day it doesn’t make any kind of huge difference.
Figure 10,000 miles driven, times 4 corners, totals 40,000 total tire miles. Divide 40,000 by five tires and you get 8,000 miles put on each tire, versus 10,000 miles per tire if you use a four tire rotation over that same 40,000 miles.
Another way to look at it is if a set of four tires will last 40,000 miles, adding the fifth tire will give the entire set a lifetime of 50,000 miles.
You still need to replace when the tires are worn. You’ll replace four tires at 40k with a four tire rotation and you’ll replace five tires at 50k with a five tire rotation.
If you want to have fun with mathematics you could figure switching from a five tire rotation to a four tire once the original set of five is used up, keeping one of the worn tires as the spare.
Bottom line is that if you drive lots of miles you’ll need to replace tires.
Being a full time Minnesotan for most of my life I did an eight tire rotation; summer wheel set and winter wheel set for all vehicles. I drove a lot. Using two sets did not save me any money, nor did it cost very much more...just a second set of wheels per vehicle.
Using two sets did let me have the best tires for summer and winter use. And it made it easy for me to rotate them myself for the season change.
Like I said, there are a lot of ways to look at this. I use a six tire set on my Raptor and rotate them all into service...using four or five might work best for someone else.
Fun...and yes, I’m punchy tonight...just watched the Twins get beat by the Tigers.
