Best tyre size for fuel economy

[Cuppa]

I have a GQ Patrol with 4.2 TB42E engine with 265/70/R16 tires on 8 inch rims.
The driving I mostly do is open road with a little dirt track activity on farms.

I would like to know from someone who knows the real skinny on tires.

What is the correct size tire for the best fuel efficiency. I have heard that the wider the tire the more energy it takes to move it.
I have also heard that if your tire is too tall then you use up fuel to overcome the oversize rolling diameter.

What size size should I get? Skinny tall 235/85R16? Wide tall 255/85R16?
Or maybe I will have to get different size rims.

I just need the correct advice.

Thanks

Neil

My ex Telstra truck came with 235/85’s on split rims. I have since replaced them with 265/75’s & non split rims.

The total weight of the 265 + steel rim is, despite there being more rubber, lighter than a split rim with 235, quite noticeably.

The diameter of the 265/75 is almost identical to the 235/85. Just a bit wider.

On my truck I needed to run the 235’s at 68psi on the rear. With the 265’s I have been able to drop this to mid 40’s.

I haven’t noticed any real change to fuel consumption, but comfort on rough roads is greatly improved.

However as part of your decision making you might want to consider why Telstra stuck with the 235’s (mine was used in the red centre based out of Alice Springs & did a lot of rocky & sandy dirt roads).

My motivation to change was that I felt the higher pressures would put me at higher risk of blowouts & I also wanted to improve ride comfort.
I decided that as I carry two spares that I would rather just carry a ‘plug repair kit’ than deal with split rim repairs by the side of the road.
I also guess I succumbed to a degree of pressure from fellow forum members here where bigger & wider tyres are almost universally held in higher esteem than skinny ‘cheese cutters’ (to be fair, a view probably held by the majority of 4wd’ers in general).
Aesthetics/fashion plays a part, but there are some off road situations where wider tyres are certainly an advantage.
I don’t regret my decision to go a bit wider for my intended usage - long term touring, & would do thesame again.
Being able to physically lift a wheel more easily is a bonus for a small bloke like me.