ElpiAuto255/40R19 vs 275/35R19
275/35R19 is 0.45″ (12 mm) shorter than 255/40R19, a 1.7% difference in overall diameter — right at the edge of the ±3% band — fine on most cars, but check clearance at full lock and full suspension compression.
| Measurement | 255/40R19 | 275/35R19 | Difference | % |
|---|---|---|---|---|
| Overall diameter | 27.03″ | 26.58″ | −0.45″ | −1.7% |
| Section width | 10.04″ | 10.83″ | +0.79″ | +7.8% |
| Sidewall height | 4.02″ | 3.79″ | −0.23″ | −5.6% |
| Circumference | 84.92″ | 83.50″ | −1.42″ | −1.7% |
| Revs per mile | 746.1 | 758.8 | +12.7 | +1.7% |
| Revs per km | 463.6 | 471.5 | +7.9 | +1.7% |
Speedometer: with 255/40R19 as the original, 275/35R19 makes an indicated 60 mph really about 59.0 mph, and the axle sits ~0.23″ lower.
Reading this comparison
The overall diameter is what matters here: 255/40R19 is the taller tire. It sets ride height, gearing and how far the tire travels per revolution — which is what the speedometer and odometer count. Width and sidewall change fit and feel (a wider tire needs a wider wheel and more clearance; a shorter sidewall sharpens steering) but not the gearing.
Figures are geometric estimates from the size codes; real moulded tires vary by brand by 1–3%. Confirm load rating, wheel width and physical clearance on your vehicle before fitting. To compare any other two sizes, use the tire size comparison tool; to decode one size and see what else fits its wheel, the tire size calculator.