What tire size does the John Deere 4020 use?
The common John Deere 4020 row-crop tire size is 6.00-16 front and 15.5-38 rear. Some standard-model 4020 listings show 7.50-18 front and 18.4-34 rear. Before buying tires, check the rims already fitted to your tractor because many 4020 tractors have been changed, restored, converted, or fitted with different wheels over time.
John Deere 4020 Tire Size: 6.00-16 Front / 15.5-38 Rear
The common row-crop John Deere 4020 setup is 6.00-16 front tires and 15.5-38 rear tires. Standard models are often listed with 7.50-18 front and 18.4-34 rear tires.
60 to 91 inches, with wider settings possible on long or extra-long axles
Best simple answer: most people searching John Deere 4020 tire size want the row-crop setup: 6.00-16 front and 15.5-38 rear. If you have a standard model or changed wheels, you may need 7.50-18 front and 18.4-34 rear instead.
John Deere 4020 Row-Crop Tire Size
The common John Deere 4020 row-crop tire setup is 6.00-16 front and 15.5-38 rear. This is the main setup to target for a typical 4020 row-crop tractor, especially when the tractor still has its original-style 38 inch rear rims.
Row-Crop Tire Position
Correct Size
Owner Notes
Front Tires
6.00-16
Common row-crop steering tire size.
Rear Tires
15.5-38
Common row-crop rear drive tire size.
Rear Rim Diameter
38 inches
A 15.5-38 tire requires a 38 inch rear rim.
Best Use
Row-crop and general field work
Good fit for cultivation, planting, spraying, and general farm use.
John Deere 4020 Standard Tire Size
Some John Deere 4020 standard-model listings show 7.50-18 front and 18.4-34 rear. This setup uses a larger 18 inch front rim and a 34 inch rear rim instead of the common row-crop 38 inch rear rim.
Standard Tire Position
Listed Size
Owner Notes
Front Tires
7.50-18
Standard / alternate front tire size listed for some 4020 standard tractors.
Rear Tires
18.4-34
Standard / alternate rear tire size listed for some 4020 standard tractors.
Rear Rim Diameter
34 inches
An 18.4-34 tire requires a 34 inch rear rim.
Best Use
General farm and utility work
Wider rear footprint than the 15.5-38 row-crop tire.
How to Read John Deere 4020 Tire Sizes
Older tractor sizes such as 15.5-38 and 18.4-34 use traditional agricultural tire sizing. The first number is the approximate tire width in inches. The last number is the rim diameter in inches.
Tire Size
Meaning
Common 4020 Use
6.00-16
About 6 inches wide, fits a 16 inch rim
Row-crop front tire
15.5-38
About 15.5 inches wide, fits a 38 inch rim
Row-crop rear tire
7.50-18
About 7.5 inches wide, fits an 18 inch rim
Standard / alternate front tire
18.4-34
About 18.4 inches wide, fits a 34 inch rim
Standard / alternate rear tire
Best Replacement Tires for a John Deere 4020
The best replacement tires for a John Deere 4020 depend on the tractor version, rim diameter, and use. For a common row-crop 4020, use 6.00-16 front ribbed tires and 15.5-38 R-1 rear agricultural tires. For a standard or converted tractor, verify whether it uses 7.50-18 and 18.4-34 instead.
Replacement Target
Recommended Spec
Why It Matters
Row-crop front tires
6.00-16 ribbed front tractor tires
Maintains common row-crop front tire fitment and steering height.
Row-crop rear tires
15.5-38 R-1 agricultural tires
Matches common row-crop rear rim size and field traction needs.
Standard / alternate front tires
7.50-18 front tractor tires
Fits tractors equipped with 18 inch front rims.
Standard / alternate rear tires
18.4-34 R-1 agricultural tires
Fits tractors equipped with 34 inch rear rims.
Rear tread type
R-1 agricultural lug
Best normal choice for field traction and farm work.
Front tread type
Ribbed tractor front
Best normal choice for steering control and field use.
Owner tip: do not order tires from the model number alone. Read the size molded on your current tire and confirm the rim diameter before buying.
John Deere 4020 Tire Pressure
There is no single correct tire pressure for every John Deere 4020. Tire pressure depends on tire size, ply rating, bias vs radial construction, axle load, loader use, ballast, duals, road travel, and field conditions. Use the tire manufacturer’s load-inflation chart and never exceed the tire sidewall maximum.
Use Case
Pressure Guidance
Why It Matters
Light field work
Use tire maker load chart for your tire size and axle weight
Improves traction and reduces soil compaction.
Loader work
Front tires may need higher pressure within tire limits
Loader weight puts extra load on the front axle.
Road travel
Use pressure suitable for speed, load, and tire rating
Reduces heat buildup, squirm, and tire wear.
Fluid ballast or wheel weights
Recheck inflation after adding weight
More weight changes the load carried by the tire.
Blunt verdict: don’t copy a random PSI from a forum. A 4020 might be light, ballasted, loaded, carrying a front loader, or running duals. Tire pressure has to match the tire and the load.
John Deere 4020 Rim Size and Fitment
The tire size tells you the rim diameter. A 15.5-38 rear tire fits a 38 inch rear rim. An 18.4-34 rear tire fits a 34 inch rear rim. These are not interchangeable without changing rims.
Tire Size
Rim Diameter
Fitment Note
6.00-16
16 inch front rim
Common row-crop front fitment.
15.5-38
38 inch rear rim
Common row-crop rear fitment.
7.50-18
18 inch front rim
Standard / alternate front fitment.
18.4-34
34 inch rear rim
Standard / alternate rear fitment.
Row-Crop vs Standard Tire Setup
Row-Crop 4020
6.00-16 / 15.5-38
The most common 4020 search result and the main original-style setup for row-crop tractors.
Standard / Alternate 4020
7.50-18 / 18.4-34
Used on some standard-model listings or tractors equipped with different wheel/rim setups.
John Deere 4020 Front Tire Options
The common row-crop front tire is 6.00-16. A standard or alternate setup may use 7.50-18. Loader tractors may need a stronger ply rating or a more suitable front tire based on axle load.
Search Term
Likely Answer
John Deere 4020 front tire size
Usually 6.00-16 on row-crop tractors.
John Deere 4020 wide front tire size
Often 6.00-16, but check your actual front rim.
John Deere 4020 standard front tire
Often listed as 7.50-18.
John Deere 4020 loader front tires
Use correct size plus adequate ply/load rating for loader work.
John Deere 4020 Rear Tire Options
The common row-crop rear tire is 15.5-38. A standard or alternate setup may use 18.4-34. Many old 4020 tractors have had tire and rim changes, so the current rim diameter matters more than the original brochure spec.
Search Term
Likely Answer
John Deere 4020 rear tire size
Usually 15.5-38 for row-crop tractors.
John Deere 4020 row crop rear tire
15.5-38.
John Deere 4020 standard rear tire
Often listed as 18.4-34.
John Deere 4020 18.4-34 tires
Used on standard or converted setups with 34 inch rear rims.
John Deere 4020 15.5-38 tires
Used on common row-crop setups with 38 inch rear rims.
Tube, Tubeless, Ballast, and Duals
Many John Deere 4020 tractors use tubes in the rear tires, especially if the rims are older, rusty, or have been exposed to calcium chloride ballast. Tubeless can work on suitable rims and tires, but old tractor rims often make tubes the practical choice.
Best for Original Fit
Match the original row-crop or standard tire size that fits your current rim diameter.
Good for Traction
R-1 rear tires, fluid ballast, cast weights, or duals can help traction if pressure and axle load are correct.
Avoid
Wrong rim diameter, mismatched rear tires, dry-rotted tires, weak ply rating, and loader work on underrated front tires.
Common John Deere 4020 Tire Problems
Problem
Likely Cause
Fix
Rear tires spin too easily
Worn lugs, wrong pressure, not enough ballast, or poor soil conditions
Check tread depth, pressure, ballast, and tire type.
Front tires fail with loader
Underrated front tires, low pressure, or overload
Use correct ply/load rating and proper inflation.
Tractor sits nose-high or nose-low
Wrong front/rear tire combination
Check tire sizes against rim diameter and tractor version.
Rear tire leaks slowly
Old tube, rim corrosion, valve stem, calcium chloride damage, or bead issue
Inspect rim and tube; repair rim before installing a new tire.
Uneven rear tire wear
Road travel, wrong pressure, misalignment, or mismatched tires
Match tires, set pressure correctly, and inspect steering/axle setup.
Poor steering
Wrong front tire pressure, worn front tires, loader weight, or steering wear
Check front tires before blaming steering parts.
John Deere 4020 Tire Size Comparison
Rear Tire Width and Rim Comparison
Row-crop rear tire width 15.5 inches
Standard rear tire width 18.4 inches
Row-crop rear rim diameter 38 inches
Standard rear rim diameter 34 inches
Replacement Buying Checklist
Check This
Correct 4020 Target
Current front tire size
Read the size on your actual tire before ordering
Current rear tire size
Read the size on your actual rear tire and confirm rim diameter
Common row-crop front tire
6.00-16
Common row-crop rear tire
15.5-38
Standard / alternate front tire
7.50-18
Standard / alternate rear tire
18.4-34
Rear rim diameter
38 inch for 15.5-38, 34 inch for 18.4-34
Rear tread type
R-1 agricultural lug for normal farm work
Front tread type
Ribbed tractor front tire for steering
Ballast
Check whether tires are fluid-filled or weighted before removal
Inflation pressure
Use tire sidewall and tire manufacturer load chart
John Deere 4020 Tire Size Questions
What size are the front tires on a John Deere 4020?
The common row-crop John Deere 4020 front tire size is 6.00-16. Some standard or alternate setups use 7.50-18.
What size are the rear tires on a John Deere 4020?
The common row-crop John Deere 4020 rear tire size is 15.5-38. Some standard or alternate setups use 18.4-34.
What is the common John Deere 4020 row-crop tire size?
The common row-crop setup is 6.00-16 front and 15.5-38 rear.
What is the John Deere 4020 standard tire size?
Some standard-model listings show 7.50-18 front and 18.4-34 rear.
Can I put 18.4-34 tires on a John Deere 4020?
Yes, if the tractor has compatible 34 inch rear rims and the tire clears the tractor and fenders.
Can I put 15.5-38 tires on a John Deere 4020?
Yes. 15.5-38 is the common row-crop rear tire size, but it requires 38 inch rear rims.
What tire pressure should a John Deere 4020 use?
There is no single universal psi. Use the tire sidewall and the tire manufacturer’s load-inflation chart based on tire size, load, ballast, and use.
Are John Deere 4020 rear tires tubeless?
Some setups may be tubeless, but many older 4020 tractors use tubes because of old rims, rim corrosion, or ballast damage.
What are the best rear tires for a John Deere 4020?
For normal farm work, use R-1 agricultural lug tires in the correct size: 15.5-38 for common row-crop setups or 18.4-34 for compatible standard setups.
Do John Deere 4020 tractors use dual rear tires?
Some do, but dual fitment depends on axle length, wheel hardware, spacing, tire size, and the job.
John Deere 4020 Tire Size Summary
Common row-crop front tire: 6.00-16.
Common row-crop rear tire: 15.5-38.
Standard / alternate front tire: 7.50-18.
Standard / alternate rear tire: 18.4-34.
Common rear tread: R-1 agricultural lug.
Common front tread: ribbed tractor front tire.
Front tread width range: 48.5 to 82.25 inches.
Rear tread width range: 60 to 91 inches, wider with long or extra-long axles.
Best owner answer: most row-crop 4020 tractors use 6.00-16 front and 15.5-38 rear tires.
Last checked: John Deere 4020 row-crop tire sizes, standard/alternate tire sizes, tread width ranges, rim fitment, and replacement tire guidance checked against tractor specification references.
