On Wed, 19 Jul 2017 17:48:13 -0400,
wrote:

Depends on the rims. The 16 inch torque thrust rims on my ranger weigh
less than either the 14 inch "deerfoot" alloys from the factory OR the
stock steel wheels.Yess, the 235/70 LT tires DO weigh more than the
205/75 passenger tires that came on the truck

Of course you can put carbon fiber rims on to replace oem steel rims and
then one can argue that the "larger" carbon-fiber rims weigh less - but
apples to apples - if you change the diameter upward using the same
material rims, the weight should always go up.

However, in the articles I read, I wasn't sure if the weight would always
go up if you kept the diameter the same, and only increased the rim
diameter, since you're essentially replacing rubber with steel.

Does anyone know if, apples to apples, you increase a rim by one inch,
whether the decrease in sidewall rubber compensates enough to counteract
the gain in rim weight?

That depends ENTIRELY on the particular vehicle (some will get better
mileage, some worse - generally the higher powered cars gain, the
lower powered loose) and how the car is driven (usually an improvement
in "sane" steady speed generally level driving, and generally worse in
city or stop/start driving, or "leadfooting" on the highway)

Apparently this is an age-old argument sort of like the "what oil" or "blue
or green coolant" arguments that shadetree mechanics always seem to have an
opinion on that isn't based in any science.

It seems from most of the referenced articles that, realistically, there's
no change in gas mileage for an inch change in diameter simply because of
all the other factors involved in the real world.

However, if it was truly an apples to apples comparison, with only the one
inch diameter gain, and the tire not compensated for in overall size, then
the torque factor kicks in as the most important, with only cars with spare
torque faring well - the rest faring poorly.

That's what the references said anyway.