The Cessna 120-140 Association Forum

Can I legally put 8.00 X 6.00 tires on my 6.00 wheels without
STC filing etc?

Is the ground handling experience much different? I plan to fly
to a lot of grass and back county locations and would like the
extra diameter for rougher fields.

Disclaimer: My opinion is worth what you paid for it.

8.00-6 4-ply tires are on the type certificate for the Goodyear wheels. If you’ve had Cleveland’s installed by STC, that STC specifies a specific tire size, and that’s what you’re legal to run. I’ve asked this question of a couple A&P IAs and their suggestion was to log the 8.00s as a minor alteration. I haven’t done it yet to my plane. Talk to your mechanic, as it will be up to him or her to certify your airplane.

-Lance

The (same) tires are listed separate from the wheels on the 140a TC, so, I'd install them with a log entry and be done with it. No use in stirring up a hornet's nest.

If it's listed on the TCDS then it doesn't even rise to the level of a minor modification.

I put these tires on my plane about a year ago. My Mechanic didn’t even make a note of it, other that a W&B adjustment, as they are on the original type. I lost about 4 mph, as best as I can figure, on cruise. However, I will never go back. They make a huge difference on rough strips.

I found the STC for 140 on the website here. 8.00 x 6.00 were OK on the original Goodyear wheels so
I guess on the Clevelands it would not be out of the question.