Why?

The change is so small it will be unnoticeable. A taller set of tires would be cheaper in the long run.

 

how tall would have to go to make the difference?

 

Some 33's, 285's, or 305's are nice combo with 410s. I love my 37s and 410s, it's essentially the same as 3.55s....I have enough power to bury the speedo with ease though, stock engine wouldn't like more than 33s.

 

interesting,I will check into this.whats on it now are 265/75-16,brand new when I got it.less than 2000 on them.have to be the next set.thanks for that info

 

Taller tires lower the effective axle ratio. 10% taller tires are like changing to a 3.73 ratio.

 

I am using a Mark VIII Lincoln fan on a 1995 f250. I have the two speed set up so high comes on on a thermostat low comes on with ac compressor. Works pretty well.

 

With a properly working fan clutch it's not an issue, especially on a 460 which already gets trashcan fuel economy.

 

Not an issue? Sure, cant disagree with that, especially for 90% of the people out there that won't notice anything different either way. Does it draw noticeable power? Definitely, and the hotter it gets the easier it is to notice.

As for mileage, whether or not it's actually effected depends entirely on engagement. If It's 5* outside, and your taking a trip to the grocery store, it'll never engage substantially anyway. If it's 100* and you're towing heavy, it's definitely engaging hard and using gas to turn....the fact that the truck is getting 6-8 mpg is the only reason it's irrelevant.

It's all relative, and obviously e fans aren't the norm because most people wouldn't notice a benefit one way or another...but there are circumstances where they fit, especially if max power is what you're after.

 

I think I still might play with the fans,I have the 2 10 ons and look into the mark one.right now she is coming apart to replace the oil cooler with a remote one,and remote fiters.