Tires: 265/70/R16

[-junior]

I know there is a lot of debate on the forums of stock wheel upgrades and fit.

Just upgraded my 05 stock Sport Trac from 235/70/R16 to 265/70/R16.

No lift, the Bridgestone Duelers A/T fit without rub.

I was really surprised with the A/T's expecting a rough, loud ride, but have not noticed any difference. They have a smoother ride over the stock Michelin's, but that might just be from nice new tread. Highway driving is smooth and quiet, tested up to 80mph.

The one metric I did notice was my speedometer dropped 2mph (verified via GPS)

 

[Derekjs]

I have the same size tires and my gps showed a 5mph difference. The % difference is 9.3
If you get a programmer or speedo recalibration unit, it will help in the overall performance and mpg.
Looks good

 

[Clusterpup]

Thats funny cause I have 265/75/16 and when I drive by those rader things that displays your speed, my speddo is right where its supposed to be. This is at slower speeds, I'm sure it must be off when driving on the highway. I must test it one day with my GPS.

 

[600remguy]

Your speedo isn't really off by 2 mph, it will be off by a percentage, something I've never looked in calculating properly.

 

[Derekjs]

The percentage for his set up is 9.3%. It is calculated as revolutions/mile.
the 234/70/16 is 29 inches in diameter which is 91 inches in circumference making 697 revolutions in a mile. The 265/75/16 is 31.61 inches in diameter which is 99.4 inches in circumference making 637 revolutions in a mile.

 

[JohnnyO]

Thats funny cause I have 265/75/16 and when I drive by those rader things that displays your speed, my speddo is right where its supposed to be. This is at slower speeds, I'm sure it must be off when driving on the highway. I must test it one day with my GPS.

When I had my old '05 with 265/75-16's I'd be about 10% faster than the radar signs were showing. On my '08 when the speedo says 75 the gps says 72, so I figure I can go 80.