I had a quick question regarding spare tire-
I have a left over 19" rim that fits the LR3 and I wanted to use it as a full size spare. I was just going to through a used tire on it as it will be only used in an emergency (obv).
I am currently running LT275 /65 R18 KO2s at roughly 32.7" in OA Diameter.
If I get a 255/60R19 at 31" OA Diameter (3% reduction) cause all sorts of errors with the All Wheel drive and computer?
I wanted to get 255/65R19 which is 32" OA Diameter but the choices are few and finding 1 used would be particularly challenging.
Thanks!

 

...I'm not sure what "OA" diameter is, but 275/65R18s are about 32.1" OD. Some brands are a little bigger.

Regardless, I don't think one inch will matter but I'm not sure. I don't know if anyone has ever really sought to answer this question in my 15+ years of LR3 ownership.

 

Thank you for your response!
OA is Over All sorry should have been more clear.
I just get concerned that should i have an issue, and i put on the smaller tire- the All Wheel Drive computer freaks out and disables the vehicle or causes more damage in the differential.
Thanks!

 

Okay....totally understand your concern. I went through a similar deal as did most of us running non-OE sized tires. I cannot say with any certainty if 1" in diameter will matter or not. Your best move would be to patiently keep looking to find a tire in that larger size you mentioned. Or find another 18" rim and mount a 275/65R on it. If it won't fit underneath you can always throw it in the boot.

 

I second the idea that the 5th tire should be an exact match.

 

Understood-
I had that hunch, but was looking to save a couple of bucks- AND if i did, it probably would cost more as I cause damage to the diffs.
Thanks!

 

I am not sure about "exact" match. For sure matching OD, though. You can still save a couple bucks. When I set up my larger spare, it was really tough to find 18" LR wheels, especially a one-off (I had 4 already). So after much gnashing of teeth I'd determined that an 18" rim off of an X5 would fit the LR3. I found one and had a BFG Long Trail TA tire mounted and balanced, ensuring that it is also a 275/65R size. The ODs are never going to be EXACTLY the same, since different manufacturers cite different diameters even if the sizes are the same, plus the ones on the vehicle are going to wear a little. It's a "get me home" spare only and if it's off by a quarter of an inch OD, I think it will be okay. Key word "think." Luckily I've never had to find out!

Maybe you should experiment by airing down one tire and see what the computer does....

 

Excellent point- Airing Down-
Sometimes it can be quite simple to test and yet I did not think of it! (thus proving it is def worthwhile to post here :-)

 

Well.....I should have done that myself years ago, too! Please let us know what you find out.

 

different diameter may ruin the diffs