175/70R13 vs 185/60R14: Tire Size Comparison, Diameter Difference & Speedometer Effect

Comparing 175/70R13 with 185/60R14 comes down to four numbers for each size: diameter, sidewall, circumference and revs per mile. 185/60R14 is the taller tire: its diameter is 577.6 mm against 575.2 mm, +2.4 mm (+0.4%) larger. The width changes by +10 mm (175 mm to 185 mm) and the sidewall by -11.5 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.

On this page, 175/70r13 vs 185/60r14 tire size comparison is the case in point: Before the tables, keep the context straight. These are nominal new-tire dimensions, computed from the size codes: real tyres vary slightly by brand, model, wear and inflation pressure. A +0.4% 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.

175/70R13 vs 185/60R14 side by side

Measurement 175/70R13 185/60R14 Difference
Overall diameter 575.2 mm (22.6 in) 577.6 mm (22.7 in) +2.4 mm (+0.4%)
Sidewall height 122.5 mm 111.0 mm -11.5 mm
Circumference 1807.0 mm 1814.6 mm +7.6 mm
Revolutions per mile 890.6 886.9 -3.7
Section width 175 mm 185 mm +10 mm
Rim diameter 13 in 14 in +1 in

Diameter difference between 175/70R13 and 185/60R14: +2.4 mm (+0.4%)

The diameter gap of +2.4 mm (+0.4%) 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 +7.6 mm and the revs-per-mile difference of -3.7 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: 175/70R13 to 185/60R14 and back

Going from 175/70R13 to 185/60R14, the diameter grows by +0.4%, so the true speed is the indicated speed multiplied by 1.004. At 30 mph on the dial the car is really doing 30.1 mph; at 50 mph indicated it is 50.2 mph; at 70 mph indicated it is 70.3 mph. The speedometer therefore reads low 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 185/60R14 back to 175/70R13, the error reverses exactly: the ratio becomes 0.996, so 70 mph indicated is really 69.7 mph.

Indicated speed Actual speed fitting 185/60R14 (from 175/70R13) Actual speed fitting 175/70R13 (from 185/60R14)
30 mph 30.1 mph 29.9 mph
50 mph 50.2 mph 49.8 mph
70 mph 70.3 mph 69.7 mph

Sidewall height and ride comfort: 175/70R13 vs 185/60R14

Look at the sidewalls next. 122.5 mm on 175/70R13, 111.0 mm on 185/60R14: a difference of -11.5 mm. That is the flexible part of the tire, and it is the first thing that absorbs a bump. A shorter sidewall transmits more of the road to the driver, which feels more direct but less forgiving on rough surfaces. Aspect ratio (70% vs 60%) is simply the sidewall expressed as a share of the width.

Width, grip and fuel use: 175/70R13 vs 185/60R14

The width gap is 10 mm (175 mm against 185 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 tire fits the rim: a 185 mm tire needs a rim width within the range its maker approves, and a rim that suited 175/70R13 may not suit 185/60R14. That is a separate check from the diameter comparison, and it belongs on the list before anything is fitted.

Revolutions per mile and gearing: 175/70R13 vs 185/60R14

Gearing follows the circumference. 185/60R14 covers 1814.6 mm per revolution against 1807.0 mm for 175/70R13, so it needs -3.7 fewer revolutions per mile. At a fixed road speed the engine speed drops or rises by the same 0.4% 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 185/60R14 clear after 175/70R13? What to check before fitting

Whether 185/60R14 physically fits is a question for your car, not for this table. The numbers say it is taller by 2.4 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 185 mm tire. A tire 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: 175/70R13 or 185/60R14

On this page, 175/70r13 vs 185/60r14 tire size comparison is the case in point: Weigh the four effects separately. Sidewall (-11.5 mm) for comfort. Width (+10 mm) for grip and rolling resistance. Diameter (+0.4%) 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 175/70R13 vs 185/60R14 comparisons and tools

Frequently asked questions

What is the diameter difference between 175/70R13 and 185/60R14?

185/60R14 is +2.4 mm (+0.4%) larger in diameter than 175/70R13: 577.6 mm against 575.2 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 185/60R14 instead of 175/70R13?

On this page, 175/70r13 vs 185/60r14 tire size comparison is the case in point: The error follows the diameter ratio, +0.4%. At an indicated 30 mph the true speed would be 30.1 mph, at 50 mph indicated it would be 50.2 mph, and at 70 mph indicated it would be 70.3 mph. The full table in both directions is in the speedometer section above.

Is 185/60R14 wider than 175/70R13, and does that matter?

Yes — 185/60R14 is 185 mm wide against 175 mm for 175/70R13, a difference of +10 mm. A wider tire 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 185/60R14 fit my car if 175/70R13 fits?

Not necessarily. 185/60R14 is taller by 2.4 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 tire professional can confirm fitment on your vehicle.

Which size is better, 175/70R13 or 185/60R14?

Neither is better in general — it depends on what you want. 185/60R14 has a -11.5 mm sidewall difference, a +10 mm width difference and a +0.4% 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.