155/70R13 vs 165/60R14: Tyre Size Comparison, Diameter Difference & Speedometer Effect

Comparing 155/70R13 with 165/60R14 comes down to four numbers for each size: diameter, sidewall, circumference and revs per mile. 165/60R14 is the taller tyre: its diameter is 553.6 mm against 547.2 mm, +6.4 mm (+1.2%) larger. The width changes by +10 mm (155 mm to 165 mm) and the sidewall by -9.5 mm. This page puts both sizes side by side, works out the diameter difference in millimetres and percent, shows the speedometer error in both directions at 30, 50 and 70 mph, and explains what the change means for ride, grip and clearance — so you can judge the swap with the actual figures in front of you.

For 155/70r13 vs 165/60r14, the point is this: 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 +1.2% 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.

155/70R13 vs 165/60R14 side by side

Measurement 155/70R13 165/60R14 Difference
Overall diameter 547.2 mm (21.5 in) 553.6 mm (21.8 in) +6.4 mm (+1.2%)
Sidewall height 108.5 mm 99.0 mm -9.5 mm
Circumference 1719.1 mm 1739.2 mm +20.1 mm
Revolutions per mile 936.2 925.3 -10.9
Section width 155 mm 165 mm +10 mm
Rim diameter 13 in 14 in +1 in

Diameter difference between 155/70R13 and 165/60R14: +6.4 mm (+1.2%)

A +1.2% diameter change is small enough to sit inside the commonly used plus-or-minus 3% guideline, so the speedometer error it introduces stays modest. The circumference changes by +20.1 mm per revolution, and the revs per mile change by -10.9, which is the same story told from the car's point of view: the instruments count revolutions, so fewer revs per mile means the car travels further per revolution than the instruments assume. That drift also affects the odometer, so recorded mileage moves by the same percentage over time.

Speedometer error: 155/70R13 to 165/60R14 and back

The maths is a single ratio. 165/60R14 over 155/70R13 is 1.012, so every indicated speed after the swap is multiplied by that number to get the true speed: 30 becomes 30.4, 50 becomes 50.6 and 70 becomes 70.8 mph. In the reverse direction the ratio is 0.988, so 70 mph indicated is 69.2 mph in reality. The table below shows both directions at all three speeds, so you can check whichever direction applies to your car without doing the arithmetic yourself.

Indicated speed Actual speed fitting 165/60R14 (from 155/70R13) Actual speed fitting 155/70R13 (from 165/60R14)
30 mph 30.4 mph 29.7 mph
50 mph 50.6 mph 49.4 mph
70 mph 70.8 mph 69.2 mph

Sidewall height and ride comfort: 155/70R13 vs 165/60R14

Sidewall height moves by -9.5 mm between these two sizes (108.5 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 70% to 60%.

Width, grip and fuel use: 155/70R13 vs 165/60R14

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 155/70R13 may not suit 165/60R14. That is a separate check from the diameter comparison, and it belongs on the list before anything is fitted.

Revolutions per mile and gearing: 155/70R13 vs 165/60R14

Gearing follows the circumference. 165/60R14 covers 1739.2 mm per revolution against 1719.1 mm for 155/70R13, so it needs -10.9 fewer revolutions per mile. At a fixed road speed the engine speed drops or rises by the same 1.2% as the diameter change. With the taller size the engine sits slightly lower in the rev range at cruising speed, which some drivers like and which can help fuel use a little. Either way the effect is proportional to the diameter difference, not larger than it.

Will 165/60R14 clear after 155/70R13? What to check before fitting

Whether 165/60R14 physically fits is a question for your car, not for this table. The numbers say it is taller by 6.4 mm and 10 mm wider, and those are the dimensions that decide clearance — but the actual gaps depend on your arches, suspension and steering geometry. Check at full lock both ways, check with the suspension compressed, and check with the car loaded. Check the placard for the load index and speed rating, and check the rim width for a 165 mm tyre. A tyre professional can confirm all of it in one visit, and that confirmation is the step that turns a comparison into a fitment.

Which size suits which priority: 155/70R13 or 165/60R14

Weigh the four effects separately. Sidewall (-9.5 mm) for comfort. Width (+10 mm) for grip and rolling resistance. Diameter (+1.2%) for the speedometer, odometer and gearing. And clearance for whether the swap is physically possible at all. If the diameter is inside the plus-or-minus 3% guideline and the clearance check passes, the remaining differences are small enough to be a matter of taste; if either of those fails, the comparison is academic until it is resolved.

Related 155/70R13 vs 165/60R14 comparisons and tools

Frequently asked questions

What is the diameter difference between 155/70R13 and 165/60R14?

165/60R14 is +6.4 mm (+1.2%) larger in diameter than 155/70R13: 553.6 mm against 547.2 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 165/60R14 instead of 155/70R13?

The error follows the diameter ratio, +1.2%. At an indicated 30 mph the true speed would be 30.4 mph, at 50 mph indicated it would be 50.6 mph, and at 70 mph indicated it would be 70.8 mph. The full table in both directions is in the speedometer section above. That is the point this page works through for 155/70r13 vs 165/60r14.

Is 165/60R14 wider than 155/70R13, and does that matter?

Yes — 165/60R14 is 165 mm wide against 155 mm for 155/70R13, 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 165/60R14 fit my car if 155/70R13 fits?

Not necessarily. 165/60R14 is taller by 6.4 mm and 10 mm wider, and it needs a 14-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, 155/70R13 or 165/60R14?

Neither is better in general — it depends on what you want. 165/60R14 has a -9.5 mm sidewall difference, a +10 mm width difference and a +1.2% 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.