Driving with smaller tires on the front

[zorobabel]

I have smaller tires than stock right now - 245/70R17 on my 2009 Exp XLT EL 4x4.
I'm expecting that 2 of the tires I'll be pulling out of service in the near-ish future.
I have 2 tires (265/70R17) ready to take their place. I'm thinking of installing the larger diameter tires on the rear and only use RWD at least for a while. Not sure how all of that will be handled by the electronics on the Expedition, does anyone have experience doing something like this?

 

[BigOleFordFan]

In general, this is a bad idea, as it will cause ride & handling issues for sure, as it will shift more of the vehicle weight onto the front suspension, in addition to possibly causing some error codes to pop up on the ABS, traction control, speedometer, and anti-theft system (if equipped) and other systems...

This may be ok as a short term thing, but again, I would not want to say it will be ok long term, since most vehicles are designed with a specific center of balance and it's weight being distributed in a specific way...

You can look here to see a representation of the differences in tire sizes:

Tire Size Calculator

The best tire size calculator. Use our tire size calculator to find tire size specs and suggested tire sizes. Then check prices for all available tire sizes.

tiresize.com

 

[chuck s]

Using the compare function from the link above there's a 3.6% difference in diameter/circumference which is (guess) probably not enough difference to mess up ABS or occasional 4A driving or even 4H or 4L in an emergency.

Don't take this as my recommendation to do it though.

But why are you doing this? Spend $500 and get two more matching tires and install all 4.

(The silver car in my photo has staggered wheels. 215mm width tires on the front and 255mm width tires on the rear. But both sets of tires are within 1% of the same circumference and it's RWD.)

-- Chuck

 

[zorobabel]

Thanks BigOleFordFan and chuck s !
I guess I'll have to time the replacement with a tire sale.