I run 305/45ZR22 tires and have done for several years now. I got them for 2 main reasons; 1) they fill in the wheel wells much better and make the truck look how it should - muscle. With the 1.2 extra inch in the tires, in effect, you make the truck appear lowered by that much on top of the lowering kit, as the wheel gap is much shorter to the well, if that makes sense. 2) traction. More side wall offers greater flex which equals greater traction.
No road bounce either, I personally didn't notice any difference between the 40 and 45s, the truck glides along nicely. If anything, perhaps a little softer over bumps. I didn't notice any rpm difference at 100kph/62mph, maybe 1-2mph at most with the T56? Now I run the 4L80E I have a Compushift so it's as easy as going to the tire screen size in set up and changing it to suit. For me, there were too many reasons not too, the traction factor alone should see everyone switching IMO. So many threads on traction and everyone doing minute things yet overlooking this.
40s will give you great corner speed but lets face it, if we wanted to handle corners like CARS we wouldn't have purchased TRUCKS. These beasts are straight-liners, sure they can go around tracks OK but they are at home stomping a 1/4 or on the highway hunting for food. Someone mentioned slower acceleration? I believe larger sidewalls would equal
faster acceleration as the same rotation is being made by the axle but with a larger diameter tire it's covering more distance with the same rotation. Same principle applies to getting better MPG (which is also another bonus). Anyhow, me and The Batram have never heard a single complaint about them and as the driver, I have nothing but good to say about running 45 series tread under your beast. 2c
