14" to 15" wheel swap 86 Pup?

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LUVFishin
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14" to 15" wheel swap 86 Pup?

Post by LUVFishin »

Greetings. I am thinking about replacing the 14" wheels and 205/75r14 tires on my 86 Pup turbo diesel with the 15" wheels and 205/70r15tires from my 81 LUV diesel, and vice versa. It seems like a simple swap to me but I don't know much about these things.

Does anyone see a problem with this for either truck?

What can I expect in the 86 Pup as far as a change in performace or mileage or handling?

Thanks for any opinions. Mike
1981 Chevrolet LUV 4x4 Mikado unstoppable fishing rig

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swvaed
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Re: 14" to 15" wheel swap 86 Pup?

Post by swvaed »

I'm running 15 inch wheels from a Trooper on my 90 gas pickup that normally ran 14's. Love it, Stands a little taller, better looking wheel.
Yours is a Pup, mine's a Pickup, and I don't know the Luv at all. You'll have to translate.
Some thoughts:

Clearance: I can run up to a 225, but it rubs in a hard turn.

Bigger wheel does not always mean taller tire. I have 16 inch studded tires on rear of GMC Jimmy, 15 inch all season on front. Rear is smaller outside diameter tire. Here is a good calculator to estimate dimensions.

https://tiresize.com/calculator/

Disregarding weight (We're not talking monster tires) taller tire (Larger diameter) will slightly increase gas mileage on level ground if you can stay off the gas pedal. You're actually changing the gear ratios. Taller tire means more distance traveled per turn, but less torque. If you have to stay on the throttle or in lower gears there goes your increase in mileage. In my 'normal' driving, I have only 3 major hills to occasionally pull, so it works for me.

If it's not 4 wheel drive, mismatched tires on different axles can run, but it screws up steering geometry and headlight aim for starters and can result in abnormal tire wear. I have a junk S 10 with 31 inch tall tires on the back 225 15's on the front. Screwy steering, headlights good for hunting nightcrawlers and so little torque it will barely back up.

Bottom line: Be careful, EXPECT AND BE READY FOR IT TO GO WRONG, try it and it may go right.
92 Pickup 2.3 5spd Available/Parts/Salvage title
90 Long cab 2.6FI 5spd My project
87 PUP 1.9 4spd Available/Project/Parts/Clear title
74 VW Superbeetle Available/Clear title
61 VW Rail Available/Va. Street legal/Clear title
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JoeIsuzu
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Re: 14" to 15" wheel swap 86 Pup?

Post by JoeIsuzu »

Mike,

Some questions really depend on tire diameter, not rim diameter. I've been running 15" Trooper (?) rims for years, but I've kept my tire diameter the same as factory. No noticeable difference in performance or economy.

Jack
LUVFishin
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Re: 14" to 15" wheel swap 86 Pup?

Post by LUVFishin »

Hey thanks. I think I will give it a shot and swap them out and see how it feels, I can always swap back. The Pup on 14s feels like a little old race car but the selection in 15" tires is so much better.
1981 Chevrolet LUV 4x4 Mikado unstoppable fishing rig

http://s1126.photobucket.com/user/LUVFi ... ml?filters[user]=146033390&filters[recent]=1&sort=1&o=0
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JoeIsuzu
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Re: 14" to 15" wheel swap 86 Pup?

Post by JoeIsuzu »

LUVFishin wrote:Hey thanks. I think I will give it a shot and swap them out and see how it feels, I can always swap back. The Pup on 14s feels like a little old race car but the selection in 15" tires is so much better.

Search online for a "tire size calculator". With that, you can see what size 15" tire is the same outside diameter as your current 14" tires.

Jack
LUVFishin
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Re: 14" to 15" wheel swap 86 Pup?

Post by LUVFishin »

Dang, the tire size calculator says a 205/70/R15 is only .2 inches taller than a 205/75/R15. I thought I would get around an additional inch of clearance. So I guess the only real reason to do it is better 15" tire selection particularly for all terrain tires. It doesn't look like there are many or any all terrain 14" tires anymore based on other posts.
1981 Chevrolet LUV 4x4 Mikado unstoppable fishing rig

http://s1126.photobucket.com/user/LUVFi ... ml?filters[user]=146033390&filters[recent]=1&sort=1&o=0
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JoeIsuzu
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Re: 14" to 15" wheel swap 86 Pup?

Post by JoeIsuzu »

LUVFishin wrote:Dang, the tire size calculator says a 205/70/R15 is only .2 inches taller than a 205/75/R15.

You either have a typo or a miscalculation. The 205/70 should be slightly shorter than the 205/75.

Jack
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