Tires: Toyota Landcruiser tire size change, toyota landcruiser, safety perspective

Question
QUESTION: I am considering putting new tires on my 2005 Landcruiser that are not the same size as the factory size of 275/60/18.  The reason is that the tire I want is not available in that size.  It is available in 275/65/18 and 265/65/18 and several other close but not exact sizes.  What are your thoughts on changing sizes and which size would you go with if the factory size is not an option?  Thanks in advance.

ANSWER: Mike,

There is a lot of what I could say, but allow me to make a recommendation:  265/65R18.  It has a slightly larger load carrying capacity, so the safety issue is avoided.  It is within 2% of the same diameter, so the speedometer would be largely unaffected.  It is very similar in dimensions, so it will fit within the fenderwells.


---------- FOLLOW-UP ----------

QUESTION: Thanks for the prompt response.  If you don't mind going a little deeper in your response, I would like to be educated a bit more on the topic.  

First - I assume the 265/65 would be about a half inch narrower than the factory 276/60 so could you help me understand the safety/performance difference in going narrower?  With this being an SUV, should I be concerned with stability on a narrower tire?

Second - I assume the 275/65 would be the same width but about 1 inch larger in diameter.  I don't have a problem with the speedometer affect.  I have been told that the 275/65s fit on the vehicle but I would certainly test it out before buying.  So other than the speedometer reading being off and assuming the tire fits within the fenderwells - what are the cons to using this size tire?

Thanks again for your guidance.

Answer
Mike,

What is most important from a safety perspective is load carrying capacity - bigger is better.  Beyond that, there is so much variation from tire to tire (meaning make and model) that tire size plays a very small role in the safety consideration.  This would apply to both situations you've presented.

I think getting the speedometer correct adds more advantages than having an over sized tire does - but that's just my opinion.