Zebrafive
Super Member
MY JD 6415 (85hp) came with 18.4R-34s I was surprised it had such big tires for an open station tractor.
Last edited:
Tire Size comparison
- Thread starter hotchkiss
- Start date
MHarryE
Elite Member
- Joined
- Feb 15, 2009
- Messages
- 2,946
- Location
- Northeastern Minnesota
- Tractor
- Kubota M7-171, M5-111, SVL75-2, RTV900XT & GR2120; CaseIH 1680 combine
The 420/85R34 has an English equivalent 16.9R34, is 16.5 inches wide, and has a 188 inch rolling circumference. Tread depth is 56/32 inches. Titan list price is $3007.49. The advantages are higher load capacity, greater floatation, improved traction and smoother ride.
The 18.4R30 is 19.3 inches wide and has a 182 inch rolling circumference. Its tread depth is 50/32 inches. Titan list price is $1755.49. The advantages are tread wear and durability, maximum tread cleaning and sidehill slip resistance.
The advantages are the ones listed in the Titan book for those particular sizes.
From the John Deere sales manual, the R1W tires offer a deeper tread and are popular in wetter soils. It goes on to say that many European utility tractors use R1W tires. But 56/32 vs 50/32 doesn't seem like that much tread height difference (only 3/16 inch) but the tread patterns shown in the Titan book are very different.
Finding the right tires
The 18.4R30 is 19.3 inches wide and has a 182 inch rolling circumference. Its tread depth is 50/32 inches. Titan list price is $1755.49. The advantages are tread wear and durability, maximum tread cleaning and sidehill slip resistance.
The advantages are the ones listed in the Titan book for those particular sizes.
From the John Deere sales manual, the R1W tires offer a deeper tread and are popular in wetter soils. It goes on to say that many European utility tractors use R1W tires. But 56/32 vs 50/32 doesn't seem like that much tread height difference (only 3/16 inch) but the tread patterns shown in the Titan book are very different.
Finding the right tires