155/65R13 vs 165/60R13: Tyre Size Comparison, Diameter Difference & Speedometer Effect

If you are choosing between 155/65R13 and 165/60R13, the first question is how far apart they really are. 165/60R13 is the shorter tyre: its diameter is 528.2 mm against 531.7 mm, -3.5 mm (-0.7%) smaller. The sidewall goes from 100.8 mm to 99.0 mm (-1.8 mm), the circumference from 1670.4 mm to 1659.4 mm, and the revs per mile from 963.5 to 969.8. The tables below lay all of that out, then work through the speedometer effect in each direction and the clearance checks that matter before either size goes on the car.

Taking 155/65r13 vs 165/60r13 as the case in point: Before the tables, keep the context straight. These are nominal new-tyre dimensions, computed from the size codes: real tyres vary slightly by brand, model, wear and inflation pressure. A -0.7% difference is within the plus-or-minus 3% guideline that is commonly used for speedometer accuracy, and the speedometer tables below show exactly what that percentage means at real road speeds. The rest of the page covers sidewall, grip, gearing and the clearance checks that decide whether the larger size can physically fit.

This is a calculation, not a safety approval. Always check your vehicle's door-jamb placard, load index and speed rating, and confirm fitment with a tyre professional before fitting a different tyre size.

155/65R13 vs 165/60R13 side by side

Measurement 155/65R13 165/60R13 Difference
Overall diameter 531.7 mm (20.9 in) 528.2 mm (20.8 in) -3.5 mm (-0.7%)
Sidewall height 100.8 mm 99.0 mm -1.8 mm
Circumference 1670.4 mm 1659.4 mm -11.0 mm
Revolutions per mile 963.5 969.8 +6.3
Section width 155 mm 165 mm +10 mm
Rim diameter 13 in 13 in +0 in

Diameter difference between 155/65R13 and 165/60R13: -3.5 mm (-0.7%)

The diameter gap of -3.5 mm (-0.7%) is the number to carry away from this section. It is inside the plus-or-minus 3% guideline, and it shows up directly in the speedometer tables below. The circumference difference of -11.0 mm and the revs-per-mile difference of +6.3 are the same change expressed differently — the first is what the road sees, the second is what the car's sensors count. Neither is a safety judgement on its own; both are inputs to the fitment checks further down the page.

Speedometer error: 155/65R13 to 165/60R13 and back

Going from 155/65R13 to 165/60R13, the diameter grows by -0.7%, so the true speed is the indicated speed multiplied by 0.993. At 30 mph on the dial the car is really doing 29.8 mph; at 50 mph indicated it is 49.7 mph; at 70 mph indicated it is 69.5 mph. The speedometer therefore reads high after the change, which matters most at motorway speed, where even a small percentage is a real difference in miles per hour. Going the other way, from 165/60R13 back to 155/65R13, the error reverses exactly: the ratio becomes 1.007, so 70 mph indicated is really 70.5 mph.

Indicated speed Actual speed fitting 165/60R13 (from 155/65R13) Actual speed fitting 155/65R13 (from 165/60R13)
30 mph 29.8 mph 30.2 mph
50 mph 49.7 mph 50.3 mph
70 mph 69.5 mph 70.5 mph

Sidewall height and ride comfort: 155/65R13 vs 165/60R13

Sidewall height moves by -1.8 mm between these two sizes (100.8 mm to 99.0 mm), and that is enough to feel. A taller sidewall flexes more, which softens sharp impacts and gives the tyre more give over potholes; a shorter sidewall flexes less, which sharpens the steering response and leaves the rim closer to the road surface on a hard hit. Which of those you get depends on the direction of the change — here the sidewall shrinks — and on the aspect ratio shift from 65% to 60%.

Width, grip and fuel use: 155/65R13 vs 165/60R13

The width gap is 10 mm (155 mm against 165 mm). Going wider usually buys dry grip and a more planted feel, and it costs a little in rolling resistance and road noise. Remember that width also decides whether the tyre fits the rim: a 165 mm tyre needs a rim width within the range its maker approves, and a rim that suited 155/65R13 may not suit 165/60R13. That is a separate check from the diameter comparison, and it belongs on the list before anything is fitted.

Revolutions per mile and gearing: 155/65R13 vs 165/60R13

Gearing follows the circumference. 165/60R13 covers 1659.4 mm per revolution against 1670.4 mm for 155/65R13, so it needs +6.3 fewer revolutions per mile. At a fixed road speed the engine speed drops or rises by the same 0.7% as the diameter change. With the shorter size the engine sits slightly higher in the rev range at cruising speed, which sharpens response a little at the cost of a small amount of fuel. Either way the effect is proportional to the diameter difference, not larger than it.

Will 165/60R13 clear after 155/65R13? What to check before fitting

Do not skip the physical check. The diameter difference is -0.7% and the width difference is +10 mm, and both of those affect whether 165/60R13 fits where 155/65R13 did. Check the gap between the tyre and the arch, the gap to the suspension arms and struts, and the clearance at full steering lock in both directions. Repeat the check with weight in the car, because suspension travel changes the geometry. If the tyre touches anything at any point in that check, it does not fit, whatever the diameter percentage says. The load index and speed rating need confirming against the placard too, and the rim width must suit a 165 mm tyre.

Which size suits which priority: 155/65R13 or 165/60R13

The decision comes down to priorities. Comfort follows the sidewall (-1.8 mm here). Grip follows the width (+10 mm here). Instrument accuracy follows the diameter (-0.7% here). Gearing and cruising engine speed follow the revs-per-mile change (+6.3). None of those is large in this comparison, which is why the practical checks — clearance, load index, speed rating, rim width — deserve as much attention as the numbers. Get those right and the size choice becomes a matter of preference rather than a risk.

Related 155/65R13 vs 165/60R13 comparisons and tools

Frequently asked questions

What is the diameter difference between 155/65R13 and 165/60R13?

165/60R13 is -3.5 mm (-0.7%) smaller in diameter than 155/65R13: 528.2 mm against 531.7 mm. That is inside the commonly used plus-or-minus 3% guideline for keeping speedometer error small.

How much will my speedometer be out if I fit 165/60R13 instead of 155/65R13?

The error follows the diameter ratio, -0.7%. At an indicated 30 mph the true speed would be 29.8 mph, at 50 mph indicated it would be 49.7 mph, and at 70 mph indicated it would be 69.5 mph. The full table in both directions is in the speedometer section above.

Is 165/60R13 wider than 155/65R13, and does that matter?

Yes — 165/60R13 is 165 mm wide against 155 mm for 155/65R13, a difference of +10 mm. A wider tyre generally gives more dry grip and can increase rolling resistance and road noise slightly. Width also affects clearance, so check the arches and suspension at full lock.

Will 165/60R13 fit my car if 155/65R13 fits?

Not necessarily. 165/60R13 is shorter by 3.5 mm and 10 mm wider, and it needs a 13-inch rim. Check the wheel arches, suspension and steering lock at full lock in both directions, with the car loaded, and confirm the load index and speed rating against your door-jamb placard. A tyre professional can confirm fitment on your vehicle.

Which size is better, 155/65R13 or 165/60R13?

Neither is better in general — it depends on what you want. 165/60R13 has a -1.8 mm sidewall difference, a +10 mm width difference and a -0.7% diameter difference, so the trade-offs are comfort, grip and instrument accuracy respectively. If the diameter is within the plus-or-minus 3% guideline and the clearance check passes, the choice is a matter of preference; if not, resolve those two points first.