New to the forum. I hope this is the right subform to ask

I have a 2010 Extended Cab 2WD 2.3L auto 4.10. currently has 31x10.5 15's. what would be the best tire size for MPG for mainly city driving? what MPG would you think I would get?

Should I get the speedo recalibrated? if I don't, what is the best way to estimate the MPG?

Any suggestions on quietest tire?

Thanks for any responses

 

Thinner tires have less road contact so less friction and increased MPG, but they also have less traction, BECAUSE they have less friction, so double edged sword.

The lower a vehicle is to the ground, within reason, the better MPG it will get a highway speeds.
Rangers, and pick up trucks in general, are not aerodynamic, lol, a brick with 4 tires, and they are even LESS aerodynamic underneath, lots of cavities to catch air to slow you down, which means you have to press down more on the gas pedal.
At speed you get whats called a ground effect that neutralizes drag for air flowing under the vehicle, IF it is low enough.

Tire noise is caused by the space between the treads on a tire, higher traction tires have more space between the treads so they can grip slippery surfaces better, i.e. snow, mud, gravel.
But on pavement the air between the treads get compressed as tire rolls along, so at speed you can hear this air being compressed and then escaping, like when you clap your hands, some of that noise is caused by the air you are compressing, not just your hands coming together.
So smaller gaps will be less noisy, slicks are 0 noise, lol.


Yes you will need to have speedometer recalibrated if your new tires are less than 31" tall, width of tires don't matter, rolling distance of tire does.

A 31" tire will make 672 full rotations per mile, and if these are stock tires then that is what speedometer is calibrated for.
Look on drivers door label to see what Stock tire size was

A 28" tire will rotate 747 times per mile.

If speedometer is calibrated then you can use Odometer to get accurate MPG.

If you will be on a longer drive you can fill up, stop filling at SECOND Click off.
Get GPS app for your phone and set it a 0 miles driven, then head off on the trip, GPS app can also tell you if speedometer is accurate.
After a few hours hopefully more you can stop as gas station and refill the tank to SECOND Click off, and get the gallons used from the gas pump.
get the Miles driven from GPS

Divide miles driven by gallons used
example: 240miles driven / 9.5gal used = 25.26MPG


GPS in most cases can't compensate for altitude, so going up and down mountains GPS is not as accurate for speed or distance traveled, just a heads up, you shouldn't have too many problems with that in most of Texas

You can also get a Bluetooth OBD reader and an OBD APP for your smartphone.
You can enter your trucks info and when you fill up, and it will display real time instant MPG as you drive, so if you press down on the gas pedal instant MPG would drop, as you cruise it will go up, good feed back for "leadfooted" drivers, lol.
It does rely on speedometer so you have to get that calibrated first
It's also good for diagnostics if there's ever a problem, and it works with ANY VEHICLE sold in the US or Canada after 1995, ANY vehicle, by Law, so not a Ford thing

 

best tires are what they call LRR tires (low rolling resistance). usually came standard on prius and the like to get optimal MPG. Ride like rocks - very stiff and not the best in snow or wet due to small contact patch from being so stiff BUT if you want best MPG your gonna need em. Narrowest firmest tire you can find. (think train locomotive - 100000's lbs all on a VERY tiny contact patch of smooth steel and can roll forever)