What does 305/40R20 mean?

In 305/40R20, 305 is the tread width in millimeters (about 12.0 inches). 40 is the aspect ratio: the sidewall height is 40% of the width, or about 122 mm (4.8 inches). "R" means radial construction, which nearly all passenger and light truck tires use today. 20 is the wheel diameter in inches. Put together, the tire stands about 29.6 inches tall when new.

What do the load index and speed rating after the size mean?

The code after the size, such as 102H, tells you how much weight each tire can carry and how fast it is rated to go. The number is the load index (102 means 1,874 lbs per tire) and the letter is the speed rating (H means up to 130 mph). Your replacement tires should meet or exceed the load index and speed rating on the placard in your driver’s door jamb.

What is the difference between SL (Standard Load) and XL (Extra Load) tires?

An XL tire is built to carry more weight than an SL tire of the same size, and it reaches that higher capacity at a higher inflation pressure. Heavier crossovers, trucks, and many electric vehicles come with XL tires from the factory because of their weight. If your vehicle’s placard or original tires call for XL in 305/40R20, replace them with XL. Putting XL tires on a vehicle that only needs SL is fine, though the ride can be slightly firmer.

Can I use a different size instead of 305/40R20?

Often, yes, within limits. A common guideline is to keep the new tire’s overall diameter within about 3% of the original. For 305/40R20, which is about 29.6 inches tall, that means roughly 28.7 to 30.5 inches. A taller tire makes your speedometer read low: with a tire 3% larger, it shows about 58 mph when you’re actually going 60. Also check that the new size fits your wheel width, clears the suspension and fenders at full steering lock, and meets your vehicle’s load rating. When in doubt, ask a tire installer before switching.

Why do prices for the same 305/40R20 tire vary across retailers?

Each retailer sets its own prices and runs its own promotions. The total you pay also depends on shipping costs, installation and disposal fees, road hazard coverage, and manufacturer mail-in rebates, which can be worth $50 to $100 or more on a set of four. Stock and pricing can also vary by region. Compare the full cost at checkout, not only the tire price.

Do the prices shown include installation or shipping?

The prices we show are the per-tire prices listed by each retailer. Shipping, installation, taxes, and fees depend on the retailer and your location, and are shown at the retailer’s checkout.

Should I replace all four tires at once?

Replacing all four keeps handling and braking even. If you replace only two, most tire makers recommend putting the new pair on the rear axle to help prevent oversteer on wet roads. All-wheel-drive vehicles often need all four tires to have closely matched tread depth to protect the drivetrain, so check your owner’s manual before replacing only some.

305/40R20 Tires — Compare Prices from 2026 | TreadCompass

Find the right tires. Clearly.

Compare prices across retailers. No rankings based on commission.

Search by Tire Size

Width

Ratio

Rim

Staggered setup (different rear size)

Standard: 225/45R17 · Off-Road: 35/12.50R17

This page contains affiliate links. TreadCompass may earn a commission when you purchase through these links, at no extra cost to you. Learn more

All Tires(41)

305/40R20

Sort:

Shows only well-known tire manufacturers: Michelin, Bridgestone, Goodyear, Continental, Pirelli, Hankook, and 14 more established brands. Filters out lesser-known or budget brands.

Gripmax SureGrip Pro Sport

305/40R20 112Y

Sale

UHP Summer

4.5(2)

The Gripmax SureGrip Pro Sport is a budget high-performance summer tire for sports cars, performance sedans and SUVs, with an asymmetric tread and a continuous…Full details

$600.24

for 4 tires

$150.06 per tire

at Walmart

Walmart★ Best Price

Sale

In StockLoad 112Speed Y

Save $167.32 vs next best

$600.24

for 4 tires

$150.06 per tire

was $697.16

305/40R20 Tires — Compare Prices

Find the right tires. Clearly.

All Tires(41)

Gripmax SureGrip Pro Sport

Atturo AZ810

Bridgestone DUELER H/P SPORT

Atlas Force UHP

Pirelli P ZERO (PZ4)

Kumho Crugen GT Pro

Pirelli P Zero R

Kumho Crugen GT Pro EV Ready

Kumho Crugen GT Pro HP72

Nokian Hakkapeliitta R5 SUV

Nokian Hakkapeliitta 10 SUV

Vredestein Wintrac Pro+

Vredestein Ultrac Pro

Pirelli P ZERO

Hankook Ventus S1 evo Z AS X

Continental ContiWinterContact TS830 P

Yokohama ADVAN Sport

Continental ContiWinterContact Ts830

Michelin X-Ice Snow SUV

Michelin X-Ice Snow

305/40R20 Tires — Compare Prices

Find the right tires. Clearly.

All Tires(41)

Gripmax SureGrip Pro Sport

Atturo AZ810

Bridgestone DUELER H/P SPORT

Atlas Force UHP

Pirelli P ZERO (PZ4)

Kumho Crugen GT Pro

Pirelli P Zero R

Kumho Crugen GT Pro EV Ready

Kumho Crugen GT Pro HP72

Nokian Hakkapeliitta R5 SUV

Nokian Hakkapeliitta 10 SUV

Vredestein Wintrac Pro+

Vredestein Ultrac Pro

Pirelli P ZERO

Hankook Ventus S1 evo Z AS X

Continental ContiWinterContact TS830 P

Yokohama ADVAN Sport

Continental ContiWinterContact Ts830

Michelin X-Ice Snow SUV

Michelin X-Ice Snow

305/40R20 tire FAQ

What does 305/40R20 mean?

What do the load index and speed rating after the size mean?

What is the difference between SL (Standard Load) and XL (Extra Load) tires?

Can I use a different size instead of 305/40R20?

Why do prices for the same 305/40R20 tire vary across retailers?

Do the prices shown include installation or shipping?

Should I replace all four tires at once?