Tire size choice for 8" wide rims (Ford Expedition)

[zorobabel]

I'm starting to plan for tire replacement on my 2009 Expedition.
It sees highway/road snow in winter (ski trips to Tahoe) and mountain dirt roads the rest of the time (want to deflate tires in that situation), but most of the miles are dry/wet pavement (getting to the previously mentioned places).
This is also my first 4WD vehicle, so hoping to benefit from the experiences of other folks here on the forum. I only drove it about 4k miles in the past year, so I'm not crazy about having 2 sets of tires dry rotting. I also lifted it about 2.5-3 inches.
I bought it with LT245/70R17 tires on 8" wide rims. Stock size is P265/70R17.
I think narrower tires would be better on snow, but I wonder how wise it would be to deflate (say) 255/80R17 tires seated on 8" rims. This is my chief concern at this point.
On the other side of the spectrum I am considering something like 285/70R17 on the same 8" rims, but mpg might suffer more (also not crazy on manhandling those). Not sure anything bigger will fit in the spare tire space.
Don't care about looks, don't plan to install spacers either. I do care about ground clearance.

 

[Johnny248]

You don't want to deflate/lower your PSI for snow use. They perform better at the recommended PSI.

 

[jetman]

I'm starting to plan for tire replacement on my 2009 Expedition.
It sees highway/road snow in winter (ski trips to Tahoe) and mountain dirt roads the rest of the time (want to deflate tires in that situation), but most of the miles are dry/wet pavement (getting to the previously mentioned places).
This is also my first 4WD vehicle, so hoping to benefit from the experiences of other folks here on the forum. I only drove it about 4k miles in the past year, so I'm not crazy about having 2 sets of tires dry rotting. I also lifted it about 2.5-3 inches.
I bought it with LT245/70R17 tires on 8" wide rims. Stock size is P265/70R17.
I think narrower tires would be better on snow, but I wonder how wise it would be to deflate (say) 255/80R17 tires seated on 8" rims. This is my chief concern at this point.
On the other side of the spectrum I am considering something like 285/70R17 on the same 8" rims, but mpg might suffer more (also not crazy on manhandling those). Not sure anything bigger will fit in the spare tire space.
Don't care about looks, don't plan to install spacers either. I do care about ground clearance.

 

[slacktide_bitog]

What is the width of the stock rims?

 

[2013ecof150]

That chart above seems really off. The factory wheels on my 2019 F150 are 20x8.5 and come with 275’s and you can easily fit a wider tire on there without issue.

My other set of Fuel wheels are 20x9 and have 295’s on them. Many people run 305’s on a 9 inch rim as well.

 

[cb_13]

Yeah that chart is off. As stated most Ford truck factory wheels have been 8.5 with a 275 width tire since around 04.

Guys were running 315s on OBS F350s with the stock 7” Alcoa wheel. That probably is enough sidewall bulge to cause abnormal wear but there’s no way a 265 is too wide for a 7” wheel.

Also a 265 is not ideal on a 9.5” wide wheel. I ran that set up myself and they were terrible to mount. They needed either a strap around the center of tire or ether to seat the bead.

 

[edyvw]

I'm starting to plan for tire replacement on my 2009 Expedition.
It sees highway/road snow in winter (ski trips to Tahoe) and mountain dirt roads the rest of the time (want to deflate tires in that situation), but most of the miles are dry/wet pavement (getting to the previously mentioned places).
This is also my first 4WD vehicle, so hoping to benefit from the experiences of other folks here on the forum. I only drove it about 4k miles in the past year, so I'm not crazy about having 2 sets of tires dry rotting. I also lifted it about 2.5-3 inches.
I bought it with LT245/70R17 tires on 8" wide rims. Stock size is P265/70R17.
I think narrower tires would be better on snow, but I wonder how wise it would be to deflate (say) 255/80R17 tires seated on 8" rims. This is my chief concern at this point.
On the other side of the spectrum I am considering something like 285/70R17 on the same 8" rims, but mpg might suffer more (also not crazy on manhandling those). Not sure anything bigger will fit in the spare tire space.
Don't care about looks, don't plan to install spacers either. I do care about ground clearance.

I would stick to stock size if running tires all year around.
Never deflate tires in snow. It is not sand. You want in snow narrower tire! 245/70 are also way off compared to 265/70. Your speedometer is probably off by good margin.
If running all year around same set, get yourself 265/70 R17 Michelin Defender LTX M/S2 or Continental terraincontact H/T.

 

[zorobabel]

You don't want to deflate/lower your PSI for snow use. They perform better at the recommended PSI.

Thanks, I guess I wasn't clear enough. I'll be deflating on dirt roads when there isn't snow. Can't drive on dirt roads in the mountains in snow around here, because they tend to close them in winter.

 

[zorobabel]

What is the width of the stock rims?

First post says 8" wide rims

 

[userfriendly]

245/75/17E Yokohama A/T XD GO17 on 8" wide wheels

 

[slacktide_bitog]

First post says 8" wide rims

oops, yeah I misread it. When you said you bought it on 8" rims, it sounded to me like they were aftermarket rims and not stock/OE since you mentioned the width, sorry

 

[zorobabel]

245/75/17E Yokohama A/T XD GO17 on 8" wide wheels

I thought about that size too, but I fear it may be too narrow to run at lower pressures without the risk of unseating the tire bead. Unless you're going to say you've ran them at 18psi with no problems...

 

[zorobabel]

oops, yeah I misread it. When you said you bought it on 8" rims, it sounded to me like they were aftermarket rims and not stock/OE since you mentioned the width, sorry

I guess 8" is middle of the road for that generation Expedition. I should have mentioned I have stock alloys like the attached photo.

 

[Skippy722]

Got 265/70r17 Yokohama Geolandar G015’s on my Ram. They’ve been awesome in the wild weather we’ve gotten in the past month… they’ve seen everything from dry relatively warm pavement to ice to deep snow to rain.

 

[chris719]

That chart above seems really off. The factory wheels on my 2019 F150 are 20x8.5 and come with 275’s and you can easily fit a wider tire on there without issue.

My other set of Fuel wheels are 20x9 and have 295’s on them. Many people run 305’s on a 9 inch rim as well.

That chart is fine for cars maybe not trucks with huge sidewalls. My BMW has 9" front and 10" wide rear wheels and are either 255/275 or 245/265 depending on the model. Almost every passenger car I looked at quickly fits in that chart range.

 

[userfriendly]

I thought about that size too, but I fear it may be too narrow to run at lower pressures without the risk of unseating the tire bead. Unless you're going to say you've ran them at 18psi with no problems...

245/75/17s are the stock size on GM 2500 HD work trucks. I've "run" them at 75 psi in rail yards and pulp mills without problems.
Back in the day I ran 285/75/16s & 285/70/17s on 8 inch wide wheels, because that's all we had.
Now I try and maximize wheel width to tire size when possible for improved handling, less heat build up from flex, longer tire life and possibly improved fuel economy.
This comes with a harsher ride quality, but with 17s you get some sidewall compared to 18s and 20s.

I practice what I preach. 245/70/17E General Arctic LT on 17x8 +40mm Fast Wheel HD are going on my daughter's 2022 3.6L Acadia next week. I have two sets of Fuel 20x10" for 295s and 20x9 ION and 20x9.5 Rhino for 275/65/20s. My son's 1500 has 275/70/18E on Fuel 18x9".

 

[shurguywutt]

I'd go with the wider 265/70/R17, you won't get as good gas mileage but you will get better traction. Driving a V8 @ only 4k miles/year I doubt gas mileage is much concern anyhow. Right now I have Firestone Destination LE2 245/70/R17s that are pretty old but I only get about 3k/year on my Sierra anyway. I will likely be getting 265s when I get a new set of tires.

 

[AZjeff]

On trucks you can go up a size from stock with no problems. Not sure why you'd want to go smaller from stock 265s to 245s and especially since you lifted it. You've been reading about tall skinny "pizza cutter" tires, not needed in your case. A 285/70 is less that 4% taller. A 275/70 isn't enough difference to bother with.

 

[userfriendly]

On trucks you can go up a size from stock with no problems. Not sure why you'd want to go smaller from stock 265s to 245s and especially since you lifted it. You've been reading about tall skinny "pizza cutter" tires, not needed in your case. A 285/70 is less that 4% taller. A 275/70 isn't enough difference to bother with.

Other options are 34/10.50/17 and 255/80/17.
www.tiresize.com

 

[AZjeff]

Op mentioned 255/80 as a narrow tire but it's not.