Swapping stock GT Tires for 255/50/20 All terrain Tires

ate2aqtr

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Hello. I have a silver GT that will be my daily incoming. Build date this week. Looking at Cooper, Falken or Toyo All Terrains. 3/8ths wider and 5/8 more side wall. Would 255/50/20 fit? I go some places slightly off the beaten path.
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Hello. I have a silver GT that will be my daily incoming. Build date this week. Looking at Cooper, Falken or Toyo All Terrains. 3/8ths wider and 5/8 more side wall. Would 255/50/20 fit? I go some places slightly off the beaten path.
It may work, but AT tires will have a huge effect on range. If I had to do this I would trade someone the 20" wheels for a set of 18" or just buy a set of 18" wheels. For a tire sized I would do a 225/60/18. Those are the same overall diameter and would provide some cushion. Falken makes a AT trail intended for crossovers I think Cooper just announced a AT for crossovers too
 

phidauex

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I’m not sure I’d go so wide, you really risk fender rub as you go wider. Pizza cutters are helpful for realistic off-road.

I was thinking 235/65R18 on 18” wheels for winter, raises you about 0.6”, only a bit wider and is pretty likely to fit. Lots of snows in that size, and the Toyo Open Country is available as an AT with XL load rating. I’m sure range would take a hit, but for me it would just be a few months in the winter.

Who will be the first to give it a try?
 

tuminatr

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I’m not sure I’d go so wide, you really risk fender rub as you go wider. Pizza cutters are helpful for realistic off-road.

I was thinking 235/65R18 on 18” wheels for winter, raises you about 0.6”, only a bit wider and is pretty likely to fit. Lots of snows in that size, and the Toyo Open Country is available as an AT with XL load rating. I’m sure range would take a hit, but for me it would just be a few months in the winter.

Who will be the first to give it a try?
Width is no big deal, I test fit a 275/40/20 it's height that you need to get right. A235/65/18 is about 1.5" taller you speedo would be off big time

Sizes that are really close

225/60/18
245/55/18
225/55/19
245/50/19
245/45/20
275/40/20
 

phidauex

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Width is no big deal, I test fit a 275/40/20 it's height that you need to get right. A235/65/18 is about 1.5" taller you speedo would be off big time

Sizes that are really close

225/60/18
245/55/18
225/55/19
245/50/19
245/45/20
275/40/20
Of course it is taller - that would be the whole point - no use going to a beefier tire if it isn’t taller. You only have to clear another 0.6” or so in the fender well, which looks like it will work, though I might need to put one of my wheels on a jack and fully compress the suspension to make sure. When putting oversize tires on cars you can usually go taller as long as you keep the width in check, and for most practical offroad activities (in CO at least), width isn’t as helpful as clearance. If you were driving around on beaches maybe you’d have the opposite strategy.

Speedo would be off by 4.4%, which isn’t terrible, and if the internal codes are similar to other modern Fords it should be possible to recalibrate with ForSCAN, though I haven’t dug into that too deep yet.

225/60/18 and 235/55/18 are good options if you want to keep the same circumference but want a bit more sidewall for a beefier tire.
 

tuminatr

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Of course it is taller - that would be the whole point - no use going to a beefier tire if it isn’t taller. You only have to clear another 0.6” or so in the fender well, which looks like it will work, though I might need to put one of my wheels on a jack and fully compress the suspension to make sure. When putting oversize tires on cars you can usually go taller as long as you keep the width in check, and for most practical offroad activities (in CO at least), width isn’t as helpful as clearance. If you were driving around on beaches maybe you’d have the opposite strategy.

Speedo would be off by 4.4%, which isn’t terrible, and if the internal codes are similar to other modern Fords it should be possible to recalibrate with ForSCAN, though I haven’t dug into that too deep yet.

225/60/18 and 235/55/18 are good options if you want to keep the same circumference but want a bit more sidewall for a beefier tire.
Here is skinny on changing wheel size ABS, traction and stability control, radar cruze, evasive steering assistance,, automatic breaking, gear ratieos, etc have been designed for a maximum of 3% variance. I am not going to tell you what to do it's your vehicle. Just letting you know why it's important to do it right
 
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phidauex

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Here is skinny on changing wheel size ABS, traction and stability control, radar cruze, evasive steering assistance,, automatic breaking, gear ratieos, etc have been designed for a maximum of 3% variance. I am not going to tell you what to do it's your vehicle. Just letting you know why it's important to do it right
Good point, a lot more electronic systems on this car than vehicles I’ve worked on in the past. I know some systems can be recalibrated, but would need to learn a bit more about the others before pulling the trigger. I’m comfortable with pretty aggressive vehicle modifications but I agree that it is worth doing it right.
 

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One thing got consider when going with a smaller wheel diameter, make sure that the wheel’s inner diameter clears the brake caliper.
 

tuminatr

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Good point, it looks like 18" is as small as we can go. But I have not tested That theory
 

pouyafrankie

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Let me know if you do this, OP. Would love to see what some all-terrain tires look like on the Mach-E. I frequently drive through rocky paths in Colorado and need to do this switch sooner than later
 
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ate2aqtr

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Leaning towards these: DISCOVERER AT3 4S - SIZE: 255/50R20
Iconic Silver GT due for Delivery End of October. Hopefully the power issue after 60+ mph is addressed by then!!!!

 
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