tire size
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tire size
hello,
relatively new to the truck community. purchasing a 21 f150 xlt. My package comes with the 18" tires. my question to you all -should i upgrade to the 20" tires ?What are the main plus and minus with different sized tires. I don't tow , and my off roading is exclusively limited to the beach. Thank you .
relatively new to the truck community. purchasing a 21 f150 xlt. My package comes with the 18" tires. my question to you all -should i upgrade to the 20" tires ?What are the main plus and minus with different sized tires. I don't tow , and my off roading is exclusively limited to the beach. Thank you .
Laughing Gas
Joined: May 2020
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From: Adirondacks
For your use, the difference between 18” & 20” relates to sidewall width; the same overall tire size on 18” rim has more sidewall and 20” has less sidewall. Less sidewall means slightly firmer ride but better at speed cornering because less sidewall flex. For overall road ride comfort 18” is better. The other issue is really your appearance preference.
Laughing Gas
Joined: May 2020
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From: Adirondacks
I don’t drive on beaches but I am guessing you may want to air down your tire pressure on the beach and if so the smaller 18” rim is a better setup for airing down with less risk of losing tire bead seal.
Last edited by nitebreeze; Feb 24, 2021 at 09:40 AM. Reason: Bad sentence
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For your use, the difference between 18” & 20” relates to sidewall width; the same overall tire size on 18” rim has more sidewall and 20” has less sidewall. Less sidewall means slightly firmer ride but better at speed cornering because less sidewall flex. For overall road ride comfort 18” is better. The other issue is really your appearance preference.
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Fleet Mechanic
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From: N. Texas
Please explain your logic on this.
Laughing Gas
Joined: May 2020
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From: Adirondacks
I drive unimproved dirt roads, jeep roads, truck trails, etc, so I don't air tires down and I am only relaying what I have read. The heavy off road and rock crawling community seems to pretty consistently say the smaller diameter rims are better for airing down and can go to lower pressure without bead failure. It seems that this goes back to smaller rims having more sidewall to flex. A larger rim on the same size tire just doesn't have a lot of rubber to bulge and flex. The recommended rule seems to be a rim diameter half the size of the wheel diameter, so a 35" tires is best on a 17" rim and a 33" tire is best on a 15" rim.
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More sidewall to flex means less of a chance of loosing the bead seal with low pressure in the tires. BTW 20" is not an upgrade nor is 18" a downgrade. More about looks than anything. The 18" will ride better and new tires are less expensive. the 20" has a different offset and width which gives a slightly more aggressive stance. 20" factory wheels have 33" tires and the 18s have 32" tires.
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