Tire Size

[jeedee]

Needing new tires for my 2002 4-door Ranger. Thought of getting oversized to help with MPG.....thoughts...? How much oversized could I go...?
Thanx....Charlie

 

[RonD]

Oversized/taller tires will change actual gearing lower, i.e 3.73 down to 3.45, so speedometer will be incorrect.
And if all your driving is above 60mph you may see an MPG improvement but less than 1mpg.
The lower gearing means the engine is at a lower RPM at 60mph, so in theory it will use less fuel, but this is also a function of horsepower to keep speed at 60MPH.
If you do any around town driving then that benefit would go away and MPG could go lower.
Taller tires are heavier so it takes more power to get them rolling, if they are wider as well then you have more friction so more rolling resistance.

Going with taller or wider tires is strictly a looks or traction thing, MPG shouldn't be in that as a reason to do it, at best it is a break even, at worst you will lose MPG.

Good MPG would be 4cyl with skinny tires, so.....................a Ford Focus

 

[jeedee]

Thanx Ron D....appreciated. Is 225 70 15 the original size for a 2002 4 door...?

 

[Mac]

Correct size for your truck should be on the drivers door jamb decal.
Dave

 

[RonD]

Yes ^^^

4th image down here shows the label to look for: http://www.therangerstation.com/tech_library/axle_codes.shtml