Tires and MGP

What will have more of a negative impact on MPG for a 4 cylinder Tacoma? :

-The total circumference of the outer part of the tire?

or

-The the length between the shoulders (how wide it is)

 

I would say the weight would be the biggest factor. But out of your 2 choices the circumference imo.

 

It's going to depend on how much you change the circumference and width. I doubt the two relate to MPG linearly and equally. Tread pattern and especially inflation will affect it too. I don't know the answer, but I bet someone somewhere has studied all of those things and has some nice graphs to show their effect.

 

As stated pretty much everything will impact your mpg.

Tire weight which is typically impacted by load rating of the tire, but some brands are just notoriously heavier than others.

Highway tread > All terrain > Mud Terrrain for mpg

Tire height since it changes the vehicle final ratio for every inch you move

Tire compound, there are eco friendly compounds out there now.

Tire contact patch

Try to keep the new tire choice near stock weight and your overall height increase to about 1 inch as for width 255 or 265 is where I would limit yourselfand your mpg will not be impacted very much.