3.73 vs 4.11 with bigger tires?

[dlb]

I was just thinking -- by putting larger tires on a t4 with a 4.11 trans, wouldn't that be a poor man's way of achieving the same lower rpm of a 3.73 trans? And if so, how much bigger would the tires need to be to be in the same ballpark of highway cruising rpm with a 3.73?

[rer233]

Circumference would have to be about 10% greater, so I think they'd have to be a LOT bigger.

[dlb]

Ok, I see: 3.73 + 10% (.373) = 4.103

I agree, a 10% larger tire is too much. Probably have a lot of rubbing issues. But something in the 5-6% larger range (like 195/60r15) shouldn't be too bad, and that would give a good balance of the benefits of both the 3.73 and 4.11 gearings.

I was just thinking about this while casually perusing the local sites for t4's. I've preferred the 3.73's but thought bigger tires might be an easy way to make the 4.11 more palatable.

[rer233]

Did some quick calculations on the i-net- seems a 185/70 r15 would do the trick (don't think it's gonna fit our cars without a lift- they're 2.5 inches taller than 175/70s.)

[dlb]

Wow, yeah those are huge. I just found this post of Splatterdog's where he says 195/70r14 fit without rubbing:

viewtopic.php?p=80597#p80597

and those are 8.7% bigger than stock so I'd probably aim to go no higher than that (I'm not interested in doing any lifts).

[NWMO]

Hey David,

I love a little lift, feels more “truckish” and gives some clearance. A 27” tire height isn’t uncommon, but comes with some rubbing, etc. I’m nearer 25.5” and like that size.

Chris

[LowBuckCanuck]

Hey David,

I love a little lift, feels more “truckish” and gives some clearance. A 27” tire height isn’t uncommon, but comes with some rubbing, etc. I’m nearer 25.5” and like that size.

Chris

What size tires do you have currently? I just picked up some 195/65r15s for a good price (25" tall tire) and would like to know what to expect before I get around to installing them.

[dlb]

What size tires do you have currently? I just picked up some 195/65r15s for a good price (25" tall tire) and would like to know what to expect before I get around to installing them.

https://www.1010tires.com/Tools/Tire-Si ... 195-65R15/

Looking at this, your 195/65r15 tires are only 1/4" bigger than the 195/70r14 that splatterdog said do not rub (I don't think he has any lift in his t4's) so if you get any rub it shouldn't be too bad.

[LowBuckCanuck]

What size tires do you have currently? I just picked up some 195/65r15s for a good price (25" tall tire) and would like to know what to expect before I get around to installing them.

https://www.1010tires.com/Tools/Tire-Si ... 195-65R15/

Looking at this, your 195/65r15 tires are only 1/4" bigger than the 195/70r14 that splatterdog said do not rub (I don't think he has any lift in his t4's) so if you get any rub it shouldn't be too bad.

Check em out:

20210608_173408.jpg

[NWMO]

Nice!

[NWMO]

Hey David,

I love a little lift, feels more “truckish” and gives some clearance. A 27” tire height isn’t uncommon, but comes with some rubbing, etc. I’m nearer 25.5” and like that size.

Chris

What size tires do you have currently? I just picked up some 195/65r15s for a good price (25" tall tire) and would like to know what to expect before I get around to installing them.

Hey Lowbuck,

Sorry for the slow response, I'm running 195/70R14, roughly 24.75" diameter. Last year at the meet and greet we off-roaded with at least one Tercel that had significantly taller tires on it and it did fine. However, you do get rub and I believe the owner commented on "loss of articulation". I assume when in/on the harrier obstacles, he found the tire contacting the wheel well/body when there was still suspension compensation available?

Chris