P38A What are the tallest tires you can put on a standard P38 16 inch rims ?

[LR-hobbs]

Hello all
Just wondering wether anyone has experience in fitting tall tires to a standard P38 , I found some I liked however the sizes were 235, 85, r16 , are these to tall and going to rub?


Cheers

 

[kermit_rr]

When i got my p38 it had 255/55R19 on it. They rubbed a bit of you tried hard but not a massive problem.
235/85R16 nearly 2 inches taller but half an inch narrower

 

[Datatek]

Hello all
Just wondering wether anyone has experience in fitting tall tires to a standard P38 , I found some I liked however the sizes were 235, 85, r16 , are these to tall and going to rub?


Cheers

Speedo may be wrong and technically they may be illegal as not homologated for the vehicle. Not much notice is taken of these things in the UK, but it may affect your insurance.

 

[kermit_rr]

Speedo may be wrong and technically they may be illegal as not homologated for the vehicle. Not much notice is taken of these things in the UK, but it may affect your insurance.

Good point
If the standard is 255/65R16 and that's what the car expects then the speedo will read ~60 at ~65mph

 

[kermit_rr]

Speedo may be wrong and technically they may be illegal as not homologated for the vehicle. Not much notice is taken of these things in the UK, but it may affect your insurance.

They will be interested if they catch you doing 63 in a 60!!! They will throw the book at you

 

[LR-hobbs]

Speedo may be wrong and technically they may be illegal as not homologated for the vehicle. Not much notice is taken of these things in the UK, but it may affect your insurance.

Never thought about that , are speedometer calibrations possible on the P38?

 

[P38Seb]

Tire Size Comparison

Tire size comparison the easy way. Use our tire size comparison calculator to compare diameter, width, sidewall, circumference and revolutions per mile.

tiresize.com

This can be quite a good site to see size differences and speed changes. Most speedos over read your actual speed, so indicated 60mph could be actually be 57mph for instance. Provided you don’t go too far bigger you could end up with ‘a slightly more accurate’ speedo. What it does to your car handling and insurance though

 

[LR-hobbs]

Tire Size Comparison

Tire size comparison the easy way. Use our tire size comparison calculator to compare diameter, width, sidewall, circumference and revolutions per mile.

tiresize.com

This can be quite a good site to see size differences and speed changes. Most speedos over read your actual speed, so indicated 60mph could be actually be 57mph for instance. Provided you don’t go too far bigger you could end up with ‘a slightly more accurate’ speedo. What it does to your car handling and insurance though

Yes , my goal is focused more towards comfort/fuel economy than the typical off-road car so the altered Speedo wouldn't be too much of an issue.

 

[kermit_rr]

I found the 255/65r16 comfy enough. I don't think taller tyres will help much with fool economy

 

[LR-hobbs]

I found the 255/65r16 comfy enough. I don't think taller tyres will help much with fool economy

They will give extra 1-2 mpg , the taller the better for fuel as it takes less energy to cover same distance, it's nothing to run ragged about but when the tires need changing Its worth it for me to swap over.

 

[kermit_rr]

They will give extra 1-2 mpg , the taller the better for fuel as it takes less energy to cover same distance, it's nothing to run ragged about but when the tires need changing Its worth it for me to swap over.

Will they? It will take more effort to get up to speed which will take slightly more fool

 

[P38Seb]

You’ll likely drop a few MPG - yes they’ve got a larger diameter so distance covered per rotation will be greater.. but they’ll weigh more. More mass, more energy required to rotate.

 

[kermit_rr]

You’ll likely drop a few MPG - yes they’ve got a larger diameter so distance covered per rotation will be greater.. but they’ll weigh more. More mass, more energy required to rotate.

And taller gearing

 

[MrGorsky]

Never thought about that , are speedometer calibrations possible on the P38?

I think there is a setting in Nanocom for the "tyre coefficiant" or somesuch. I always assumed that was to neaten up your speedo.... but mine's always been bang on so I never touched it!

 

[kermit_rr]

I think there is a setting in Nanocom for the "tyre coefficiant" or somesuch. I always assumed that was to neaten up your speedo.... but mine's always been bang on so I never touched it!

The tyre options for the 38 were either 255/65R16 or 255/55R18 if i recall? They both have the same circumference.

 

[LR-hobbs]

You’ll likely drop a few MPG - yes they’ve got a larger diameter so distance covered per rotation will be greater.. but they’ll weigh more. More mass, more energy required to rotate.

Id imagine if I go for narrow tires but taller they should weigh the same if not slightly more , either way I'm more than willing to trial this.

I use this car daily so for me every mpg matters.

 

[kermit_rr]

I use this car daily so for me every mpg matters.

If the primary concern is mpg then get a fiesta?
If you're using it because nothing else will do the job.. your worrying about 1 or 2 mpg???

 

[MrGorsky]

Id imagine if I go for narrow tires but taller they should weigh the same if not slightly more , either way I'm more than willing to trial this.

I use this car daily so for me every mpg matters.

It'd be interesting to see the results. I think correct pressures and road tyres (rather than some chunky A/T tread things) would have the most impact though.

 

[ovalandrover]

I think you will have trouble with the tyres rubbing the wing when turning with the car at normal height . also i think you will have trouble fitting the spare in the well in the back of the car

 

[RangeRoller dt]

I had 32s (“) on my p38. They won’t fit on as standard - no chance don’t even try it. Trust me It gears down and speedo reads wrong. You get used to it as it’s only few mph here and there until you get well over 100.
Don’t help your mpg i promise.
Any scrubbing will flag on your MOTs - you can adjust the stops but you then need to go around the moon to turn at the end of the steet, your spare won’t fit and the standard bottle Jack is now useless. If your EAS drops you could be in serious trouble.
Obviously this is a stupendous size, you may get away with a little bit but it’s the same principle