18.4/15-30 Flotation Tires

Buying 18.4/15-30 implement tires

18.4/15-30 is an older-format flotation tire used on some heavy farm implements. The 18.4 is the section width in inches and 30 is the rim diameter in inches; the /15 part belongs to an older naming system, so the easiest way to match it is a clear photo of the sidewall. It is about 18.4 inches (467 mm) wide on a 30-inch rim.

Tread choices

• I-3 traction: the usual tread for heavy implements working in soft fields.

Rim and size

Older sizes are not always made by every brand, so tell us the machine and send a sidewall photo. If an exact match is hard to find, we can look at modern sizes that fit your wheel.

• Not the same as 18.4-30: that is a standard tractor rear size with different construction. Check with us before substituting.

What to check

• Load rating: implement tires come in several ply ratings. Loaded wagons, carts and trailers on the road need the higher ratings. Match or exceed what you have.
• Tube or tubeless: many implement wheels run tubes. Tell us what you use.
• Complete wheels: if you need tire and wheel assemblies, send the bolt count and hub details. See wheels and rims.
• Used tires: implement tires often crack from sun and age before the tread wears out, so ask for the date code and sidewall photos.
• Axle sets: keep the same size and tread across an axle.

More sizes are on our implement tires and flotation tires pages. Send the quantity and delivery location for a quote.

What do 18.4/15-30 tires cost on our site?

This size is not on a model listing yet. Send us the size and we check what we can supply.

How tall is the 18.4/15-30 tire?

The nominal overall diameter is about 35.5 in (902 mm), which gives a rolling circumference near 112 in (2,834 mm). That figure is worked out from the size formula (rim plus two sidewalls). Real tires vary by make and load, so treat it as a guide and use the tire diameter calculator or the lead-lag calculator before you change size on a front-wheel-assist tractor.

Is 18.4/15-30 a radial or a bias tire?

It is a bias-ply size. The dash in the size marks bias construction, which costs less and has stiffer sidewalls. See the radial vs bias guide.