Space saver spare size for 86 442 w/G80 Posi?
- Thread starter pizza442
- Start date
So I'm not sure what the actual original compact spare "tire" size was, however the G80 vs NON G80 appears to be related to the "wheel" diameter.
G80 = 16" x 4"
NON G80 = 15" x 4"
Unless you have to have the correct configuration for a perfect restoration reason, I think by todays standards when I researched a spare for mine with the 15x7 SSIII rally wheels, and 442 tire size/height (215/65R15) you can now get an (more widely available) 18" diameter compact spare/tire to be correct for these cars.
Not sure if the size tire on this eBAY auction for a 1986 Monte SS compact spare is saying T155/80D16 which would seem to indicate it came from a G80 equipped car?
1986 Chevrolet Monte Carlo SS Goodyear OEM Convience Spare Tire T155/80D16
I can't imagine they used completely different spares for each G80 G Body (GP, GN, MCSS, 442?) that originally came with 15x7 rally wheels or mags? I don't have Chevy/Pontiac/Buick parts catalog, so can't see if they list the same.
I'm guessing 69hurstolds can likely add a ton more info from his experience, parts lookup or his vehicles.
Hope this helps
G80 = 16" x 4"
NON G80 = 15" x 4"
Unless you have to have the correct configuration for a perfect restoration reason, I think by todays standards when I researched a spare for mine with the 15x7 SSIII rally wheels, and 442 tire size/height (215/65R15) you can now get an (more widely available) 18" diameter compact spare/tire to be correct for these cars.
Not sure if the size tire on this eBAY auction for a 1986 Monte SS compact spare is saying T155/80D16 which would seem to indicate it came from a G80 equipped car?
1986 Chevrolet Monte Carlo SS Goodyear OEM Convience Spare Tire T155/80D16
I can't imagine they used completely different spares for each G80 G Body (GP, GN, MCSS, 442?) that originally came with 15x7 rally wheels or mags? I don't have Chevy/Pontiac/Buick parts catalog, so can't see if they list the same.
I'm guessing 69hurstolds can likely add a ton more info from his experience, parts lookup or his vehicles.
Hope this helps
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YUP! Different size tires for different cars. Based on information I've gleaned from looking at many tire placard door jamb decals...
Posi cars always got 16" wheels. Non-posi could have got either, mostly 15's, but it depended on the model.
Non-posi 82 Regal, 83, 85, 86 and 87 Cutlass (and 442) came with T125/70D15.
1985 442 with posi had T145/80D16. 1986 and 87 442 with posi had T155/80D16.
88 Cutlass non-posi came with T135/80D15.
84 Cutlass with posi T145/80D16. Strange. 84 Hurst/Olds non-posi had T145/80D15. Even stranger. 84 Hurst/Olds with posi had T155/80D16.
Interestingly, any and ALL Monte Carlo SS tire placards showed T155/80D16, regardless of G80 or not.
I don't have a clue why they used slightly different tires in seemingly the same type of application. I don't think it had much to do with the size of the regular wheels. I'm sure it made some difference for posi cars to have the same diameter for each side. But then, it doesn't make sense for 85 442 to use a T145 and 86-87 442 to use a T155 because they used the exact same wheel/tire combo. Weird.
Posi cars always got 16" wheels. Non-posi could have got either, mostly 15's, but it depended on the model.
Non-posi 82 Regal, 83, 85, 86 and 87 Cutlass (and 442) came with T125/70D15.
1985 442 with posi had T145/80D16. 1986 and 87 442 with posi had T155/80D16.
88 Cutlass non-posi came with T135/80D15.
84 Cutlass with posi T145/80D16. Strange. 84 Hurst/Olds non-posi had T145/80D15. Even stranger. 84 Hurst/Olds with posi had T155/80D16.
Interestingly, any and ALL Monte Carlo SS tire placards showed T155/80D16, regardless of G80 or not.
I don't have a clue why they used slightly different tires in seemingly the same type of application. I don't think it had much to do with the size of the regular wheels. I'm sure it made some difference for posi cars to have the same diameter for each side. But then, it doesn't make sense for 85 442 to use a T145 and 86-87 442 to use a T155 because they used the exact same wheel/tire combo. Weird.
Engineers? They love to change things for no reason other than it seems like a good thing. Matching stock tire size for rotation and not fighting the posi clutches does make sense though.
Wow, that's really strange all those permutations. The any and all MCSS one is strange, though I wonder if any of had to do with 7.5" vs 8.5" rear axle?
IIRC 83 H/O actually had 7.5, while 84 H/O had 8.5, and thought they all came standard with G80. I thought they only started optional G80 in 85+ 442 but who knows...
Did MCSS ever have any year that came with 8.5 rear axle? Was RPO G87 even available for Chevrolet.
I wonder what GNX came with since it had the 16" GTA wheels. Though they likely put those on in the GNXification process so maybe spare is same as all other GN's?
Cool topic... 🤔
IIRC 83 H/O actually had 7.5, while 84 H/O had 8.5, and thought they all came standard with G80. I thought they only started optional G80 in 85+ 442 but who knows...
Did MCSS ever have any year that came with 8.5 rear axle? Was RPO G87 even available for Chevrolet.
I wonder what GNX came with since it had the 16" GTA wheels. Though they likely put those on in the GNXification process so maybe spare is same as all other GN's?
Cool topic... 🤔
8.5 in turbo/GN regal and H/O or 442 only. Everything else got 7.5
The only G80 that came standard on G-body was GNX. Optional on everything else. That was it AFAIK.
The only G80 that came standard on G-body was GNX. Optional on everything else. That was it AFAIK.
If the line ticket said a number that’s what it got. Could also be depending on factory? Or as we are seeing the options ordered.
Might be factory-related. It seems the Michigan plant put on different spare sizes than the Arlington plant. But that's just a supposition based on some of the tire placards I've seen.
I would be more concerned over tire diameter over which one belongs. Being a posi rear, I would not want to have a significant difference in tire diameter side to side to burn up the clutches in the differential due to different wheel speeds. Granted You could swap a front tire to the rear and put the donut on the front if the flat was a rear tire, but if you don't have to that would be better.
GNX comes with the same T155/80D16 that's in the G80 Grand National. Both the 215/65r15 & the rear GNX 255/50ZR16's have the same 26" diameter. The GNX front tires thought are a 25.4" diameter.
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