Tire Size 275/65r18 vs 275/70r18
The key variation between the 275/65r18 and 275/70r18 tires is the overall diameter. The 275/70r18 tire size is 1.08 inches (27.5 mm) taller than the 275/65r18 tire, which means it is 3.4% larger in diameter.
| / | R |
| / | R |
| Parameter | 235/35 R18 | 205/40 R18 | Differ. |
|---|---|---|---|
| Tire Height | |||
| Section Width | |||
| Circumference | |||
| Sidewall Height | |||
| Revolutions | |||
| Rim Size |
Fitment Guide
When replacing tires, staying within 3% of the original size’s overall diameter is advisable. Going beyond this threshold may require modifications like lifting the vehicle to prevent fitment issues.
The 275/70R18 exceeds the 3% limit, with a 3.4% larger diameter than the 275/65R18. This may necessitate a mild lift to avoid rubbing or clearance problems.
Ground Clearance
The extra 1.08 inches (27.5mm) of diameter with the 275/70R18 provides more ground clearance for off-roading or driving over obstacles.
However, this also causes a lower speedometer reading compared to the 275/65R18. The 275/65R18 reduced clearance raises the risk of scraping on hazards but gives a more accurate speedometer.
Gas Mileage
Owing to slightly less rotational mass and rolling resistance, the 275/65R18 is marginally more fuel-efficient than the 275/70R18.
The difference equates to potentially one mpg or less in actual mileage. For most drivers, gas mileage impact would be negligible between these sizes.
Ride Comfort
The taller 70 aspect ratio sidewall of the 275/70R18 absorbs road impacts better, providing a smoother ride over uneven surfaces.
Its extra cushioning dampens bumps and cracks more effectively than the 275/65R18. However, the difference is modest and mainly noticeable on very rough roads.
Aesthetics
Visually, the difference between the sizes is subtle. The 275/70R18 has a slightly taller sidewall, giving a “stretched” look compared to the 275/65R18 lower profile.
For some vehicles, this taller aesthetic suits the proportions better than an overtly low-profile appearance.
Handling & Stability
The shorter sidewall of the 275/65R18 offers sharper handling and quicker turn-in than the 275/70R18.
The extra flex of the 70 aspect ratio sidewall reduces responsiveness slightly. However, both deliver responsive, stable handling overall.
Noise & Vibration
With a stiffer sidewall, the 275/65R18 transmits more road noise and vibration into the cabin.
The 275/70R18 additional sidewall flex provides better noise isolation and damping qualities over bumps. However, differences are minor, with both sizes offering a quiet, comfortable ride.
Durability
The two sizes utilize similar tread depths and rubber compounds, resulting in comparable durability and treadwear.
Proper maintenance, like rotation, is more important for longevity than the modest size difference. Both exhibit even treadwear when maintained correctly.
Adverse Conditions
Both sizes perform similarly in wet, snowy, or muddy conditions. The extra ground clearance of the 275/70R18 gives a slight advantage off-road, while the 275/65R18 shorter sidewall adds some responsiveness. Overall, both handle adverse conditions very capably.
Speedometer Difference
The speedometer reading for 275/65r18 tires at 20 mph is 0.32 mph lower than for 275/70r18 tires at the same actual speed.
This difference of 0.32 mph is due to the slightly larger overall diameter of the 275/70r18 tires. While the speedometer reading varies between these two tire sizes, the actual speed driven remains 20 mph.
Will 275/65r18 Fit 275/70r18?
No, fitting 275/65r18 tires on a vehicle originally equipped with 275/70r18 tires is not recommended.
The difference in diameter between the two tire sizes is 3.4%, slightly exceeding the advised limit of 3%. This variance may impact speedometer accuracy and handling.
How Much Taller Is A 275/70r18 Tire Than A 275/65r18?
The 275/70R18 tire is 1.08 inches (27.5 mm) taller than the 275/65R18 tire, representing a 3.4% increase in diameter.
The 275/70r18 tire has an overall height of 33.16 inches or 842.2mm, While the 275/65r18 tire’s height is 32.07 inches or 814.7mm.
What Does 275/70R18 Mean?
The tire size “275/70R18” signifies a tire with a width of 275 millimeters, an aspect ratio of 70 (indicating the sidewall height is 70% of the width), radial construction denoted by “R,” and designed for an 18-inch wheel rim diameter.
This alphanumeric code provides key specifications for selecting an appropriately sized tire for a vehicle. In inches, the tire 275/70R18 is equal to the dimensions of 33.2×10.8R18.
What Does 275/65R18 Mean?
The tire size “275/65R18” denotes a tire with a width of 275 millimeters, an aspect ratio of 65 (indicating the sidewall height is 65% of the width), and radial construction (“R”).
The number “18” signifies the diameter of the wheel rim in inches that the tire is designed to fit. When expressed in inches, the size of 275/65R18 matches that of 32.1×10.8R18.
How Wide Is A 275/70R18 Tire?
The “275” in the tire size “275/65R18” indicates the tire’s width. Therefore, a 275/65R18 tire is 275 millimeters wide.
The width of the tire, measured from the inner edge of one sidewall to the outer edge of the opposing sidewall, is represented by this measurement.
275/70r18 vs 275/65r18
This comparison table will help you easily understand the differences between the options available.
How Wide Is A 275/65r18 Tire?
The 275/65R18 tire is 275 millimeters wide. The first number in the tire size (275) represents the tire’s width in millimeters. The distance from the interior edge to the outer edge of the tire constitutes its total width.
What Size Rim For 275/65r18?
The “18” in the tire size “275/65R18” indicates the wheel rim diameter that the tire is designed to fit. Therefore, a 275/65R18 tire is intended for an 18-inch rim.
The rim width range is 7.5 inch to 9.5 inches. Meanwhile, endorsed rim widths should inhabit the 7.5 to 9.5 inch extent, granting suitable tire-wheel
What Size Rim For 275/70R18?
The 275/70r18 tire can be mounted on an 18-inch wheel with a 7-inch wide wheel being recommended and a maximum manufacturer-suggested width of 9 inches.
Our Observation
After comparing these two tire sizes, I’m struck by how their differences come down to priorities. For my needs, I lean towards the 275/65R18 as the best fit. I don’t do serious off-roading, so the extra ground clearance of the 275/70R18 isn’t a huge benefit in my case.
More important to me is responsive handling and accurate speedometer readings for my daily commuting. Of course, others who value cushioned ride comfort and occasional trail driving may prefer the 275/70R18.
There’s no definitively “right” choice – both offer respectable performance. I’m glad I took the time to understand how each excels in key areas so I could choose the size that best aligns with my driving needs and preferences.
Meet Caitlin McCormack, a Tire Size Expert and Blogger Passionate About Everything Related to Tires. With Years of Experience in the Tire Industry, Caitlin Has Become an Expert in Tire Sizes and Their Impact on Vehicle Performance.
