Spare tire questions from a Ford noob

[sharat]

Hi y’all

I bought a new ford expedition 2023 last October. The first time I ever had to use the spare was on a the last Memorial Day where my main tire was losing air (found out a nail when swapping the spare). When the spare was mounted we had 45 psi. But after driving a few miles the spare started leaking air. Both TPMS and Manual gauge (at a local gas station) showed low psi on the spare.

When mounting the spare I noticed that the side wall of the spare looks shaved and

The spare is also the same size and dimensions as the main tires.

A few questions as a newbie to Ford.
1. Will TPMS work for spare tire ? I am guessing not, but when I mounted the spare I saw the spare show 45 psi myself and then it started going to down under 35 (red flag) on the dashboard
2. Since the tire size is the same as the main tires, can I drive at regular speed or should I use the guidelines as that of donut tire?
3. Is it safe to use a spare tire that looks shaved on the side wall and worn out.

When I went to the dealership today asking questions, they assured me that it’s absolutely usable and shows a healthy 40psi.

I am just concerned about our safety when on road.

I’ll keep this forum posted on my experiences as I get into 4th July holiday travels

Thanks in advance for guidance.
Sharat

 

[TheDoug]

There is no tpms on the spare. You may have been picking up the old tires signal that you took off.

I drive normal speeds on my spare when I have had to use it. Like you said, it is the same size as the other tires.

Now this shaved side business I don't know about mine was totally normal looking. You have a pic of what you are talking about?

 

[Left Coast Geek]

yeah, the spares I've seen, including mine, are standard 18" tires on a steel wheel. Mine is a Hankook Dynapro HT, 275/65R18 (and my Expy came with 22's)

 

[2020-MAX-Limited]

Last summer I got into the spare tire situation after owning our 2020 for 9 months. We were planning a road trip and I just wanted to get familiar with the tool and tire situation, so I lowered the wheel / tire to inspect and top-off the air. As you can see, our 2020 has 265 / 70 R 17 on steel wheel. I topped the air up to the max 51 psi. Just wish I had a better pic of the DOT date code because it looks quite weathered in these pics. Maybe next time.

BTW, if you do the math, the spare (265 / 70 R 17) is 0.3 in. shorter in diameter than the main (275 / 55 R 20). That gives a 0.96 in. shorter circumference. Less than 1 inch per rotation shouldn't affect ABS or Stability systems, I would think.

This post is a good reminder for all to become familiar with the emergency equipment and procedures of your vehicle.

 

[Alwaysthinkin]

Last summer I got into the spare tire situation after owning our 2020 for 9 months. We were planning a road trip and I just wanted to get familiar with the tool and tire situation, so I lowered the wheel / tire to inspect and top-off the air. As you can see, our 2020 has 265 / 70 R 17 on steel wheel. I topped the air up to the max 51 psi. Just wish I had a better pic of the DOT date code because it looks quite weathered in these pics. Maybe next time.

BTW, if you do the math, the spare (265 / 70 R 17) is 0.3 in. shorter in diameter than the main (275 / 55 R 20). That gives a 0.96 in. shorter circumference. Less than 1 inch per rotation shouldn't affect ABS or Stability systems, I would think.

This post is a good reminder for all to become familiar with the emergency equipment and procedures of your vehicle.

Was your spare balanced? Mine wasn't.

 

[TheDoug]

Last summer I got into the spare tire situation after owning our 2020 for 9 months. We were planning a road trip and I just wanted to get familiar with the tool and tire situation, so I lowered the wheel / tire to inspect and top-off the air. As you can see, our 2020 has 265 / 70 R 17 on steel wheel. I topped the air up to the max 51 psi. Just wish I had a better pic of the DOT date code because it looks quite weathered in these pics. Maybe next time.

BTW, if you do the math, the spare (265 / 70 R 17) is 0.3 in. shorter in diameter than the main (275 / 55 R 20). That gives a 0.96 in. shorter circumference. Less than 1 inch per rotation shouldn't affect ABS or Stability systems, I would think.

This post is a good reminder for all to become familiar with the emergency equipment and procedures of your vehicle.

Wow my spare is a different size... like Left Coast Geek said... mine is a 275/65r18 which is 32.07" (the stock tire is 32.10")

however your spare is only 31.61" which to me, is big enough difference not to drive far as its 1.3xx% smaller

 

[2020-MAX-Limited]

Was your spare balanced? Mine wasn't.

I did not look for that. Next time I get my primary tires rotated, I will re-examine the spare and evaluate for balancing / replacement based on date code and condition.

 

[2020-MAX-Limited]

Wow my spare is a different size... like Left Coast Geek said... mine is a 275/65r18 which is 32.07" (the stock tire is 32.10")

however your spare is only 31.61" which to me, is big enough difference not to drive far as its 1.3xx% smaller

My stock main tire is 275 / 55 R 20, which is 31.91 inches tall, not 32.10, so it's closer to the spare size of 31.61 inches. Maybe you have a different size main tire?

Still, I agree with your recommendation not to drive any farther than necessary on the spare, if ever needed.

 

[TheDoug]

My stock main tire is 275 / 55 R 20, which is 31.91 inches tall, not 32.10, so it's closer to the spare size of 31.61 inches. Maybe you have a different size main tire?

Still, I agree with your recommendation not to drive any farther than necessary on the spare, if ever needed.

I do... 285/45r22

I thought all trims were closer together in tire size

My bad

I drove from Dallas to Houston on the spare once and had no issues. Since then I have put a 22 inch rim with same tire size in the spare spot.

 

[duneslider]

I unfortunately have used my spare a lot more than I would have liked. That included a few hundred miles while towing and have not had any issues with it. It doesn't match the others but it works fine. Also, neither of the expeditions I have owned have TPMS on the spare. My jeep commander did have tpms on the spare and would register when placed at one of the 4 corners. I was actually kind of surprised the expedition didn't have this.