Your front tires spin faster than the back. Testing air pressure vs rolling radius. 

Ditto

Ditto x2

yea basically. turn on when spin to much.

Max pressure is where max load rating is. Heavy hauling? Air up. Simple.

The fronts are intentionally geared so they travel more feet per second/minute than the rears. The idea is that the fronts should be pulling the tractor along in most/all circumstances. If the fronts were "slower" than the rears, then in dirt, the fronts would basically be plowing the dirt ahead of them as the rears pushed the tractor forward. The optimal setup would be if they were exactly equal...but that's something that's nearly impossible to achieve in the very simple drivetrain that tractors have (no fancy diffs, clutch packs, etc in a transfer case) since, as Neil was trying to show, things such as tire pressure and tire wear can change the ratio between front and back. So, in order to ensure that the fronts are plowing...they are geared so they are always going to be "faster" than the rears in order to account for the variability mentioned. As an aside unrelated to your particular comment (which probably deserves a separate thread but /shrug here we are)....I'd like to suggest that those folks who are seeing excess wear on their fronts from all the time they spend on asphalt perhaps should learn where the lever that switches from 2wd to MFWD is located. Granted, things like using the loader on hard surfaces while having to make sharp turns all the time is hard on the fronts, but Neil seemed to insinuate that the wear was due to the difference in speeds between the fronts and the backs and for that purpose any excess wear observed is due to operator error.

Totally makes sense to have the fronts go slightly faster so that they are not plowing. I've driven enough times in snow in a 2wd pickup to notice it's usually good enough unless the snow gets deep enough that the fronts are trying to push snow rather than roll on top. Thanks for your reply

There are two things: the larger the tyre the larger the impact AND it's the front to rear ratio that counts. Carrying heavy implement on the rear in wlnter means need to inflate (weight and temperature) and if that air isn't let out when summer comes ih messes up the ratio. Same if AG-tyres are used when doing heavy lifting/moving with front loader. The biggest risk is destroying the front differential if the ratio is wrong. Bug onlh using 4WD when needed and in low gear is a good rule. Larger/newer tractors disengage 4WD automatically when speed gets higher...

No.

​@@guyprattii3115 care to elaborate?

Diameter is 2*pi*r. If the radius changes, the diameter changes. That seems logical enough. But there is an argument that the radius is only changing at the very bottom of the wheel (where it's squished). At the front of the contact point, the tire is probably still the same radius. And that bit must also be part of the diameter......so there is something to what you're saying. Maybe that's why Neil found no difference?

No

Ride and traction

Also, R4 tires. Thanks for any input 👍

Best advice is see what your tire ratings are (max load @ max psi). Estimate the weight how heavy your tractor is what it is pulling or carrying on average. There might be some tire inflation charts in your manual or from the tire manufacturer that can help you decide, and also specifications either in the manual or online can give you an idea. If you're not carrying heavy loads, you can drop the pressure down quite a ways without much worry. Since they are loaded, would definitely stay 12 psi and above. Tires that are loaded will give better performance of the tractor, but reduces ride quality due to the fluid not allowing as much give.

​@farming4g Thanks for the response 👍👍👍

As far as I know, only lead in machines where front and rear tire sizes are different. Wheel loaders and 4wd articulated should theoretically have none. There might be some cases where the front might have a lead with machines that are not full-time 4WD.