195/60R15 vs 185/60R16: Tyre Size Comparison, Diameter Difference & Speedometer Effect

Comparing 195/60R15 with 185/60R16 comes down to four numbers for each size: diameter, sidewall, circumference and revs per mile. 185/60R16 is the taller tyre: its diameter is 628.4 mm against 615.0 mm, +13.4 mm (+2.2%) larger. The width changes by -10 mm (195 mm to 185 mm) and the sidewall by -6.0 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.

Two things decide whether this swap makes sense: the diameter difference and the physical fit. On diameter, 185/60R16 is +2.2% larger than 195/60R15, which is inside the plus-or-minus 3% guideline. On physical fit, the width change of -10 mm and the rim change from 15 to 16 inches both need checking against the arches, suspension and steering lock. The sections below take each of those in turn, with the numbers worked out rather than asserted.

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.

195/60R15 vs 185/60R16 side by side

Measurement 195/60R15 185/60R16 Difference
Overall diameter 615.0 mm (24.2 in) 628.4 mm (24.7 in) +13.4 mm (+2.2%)
Sidewall height 117.0 mm 111.0 mm -6.0 mm
Circumference 1932.1 mm 1974.2 mm +42.1 mm
Revolutions per mile 833.0 815.2 -17.8
Section width 195 mm 185 mm -10 mm
Rim diameter 15 in 16 in +1 in

Diameter difference between 195/60R15 and 185/60R16: +13.4 mm (+2.2%)

The diameter gap of +13.4 mm (+2.2%) 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 +42.1 mm and the revs-per-mile difference of -17.8 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: 195/60R15 to 185/60R16 and back

Here is what the speedometer does in practice. Fit 185/60R16 where 195/60R15 was, and the dial understates or overstates speed by 2.2%: indicated 30 mph is really 30.7 mph, indicated 50 mph is really 51.1 mph, and indicated 70 mph is really 71.5 mph. Swap back from 185/60R16 to 195/60R15 and the error flips sign — 70 mph indicated becomes 68.5 mph. The odometer drifts by the same percentage in each direction, so recorded mileage and any service intervals based on it shift too.

Indicated speed Actual speed fitting 185/60R16 (from 195/60R15) Actual speed fitting 195/60R15 (from 185/60R16)
30 mph 30.7 mph 29.4 mph
50 mph 51.1 mph 48.9 mph
70 mph 71.5 mph 68.5 mph

Sidewall height and ride comfort: 195/60R15 vs 185/60R16

Sidewall height moves by -6.0 mm between these two sizes (117.0 mm to 111.0 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 60% to 60%.

Width, grip and fuel use: 195/60R15 vs 185/60R16

Width changes by -10 mm, from 195 mm to 185 mm. A narrower tyre puts a smaller contact patch on the road, which generally reduces rolling resistance and can help in standing water, but it gives up some dry grip compared with the wider size. Fuel use moves with rolling resistance, so a wider tyre can cost a small amount of fuel over time — the effect is real but modest for a change of this size, and it is not something this page can put a precise number on without knowing the exact tyre models involved. That is the point this page works through for 195/60r15 vs 185/60r16.

Revolutions per mile and gearing: 195/60R15 vs 185/60R16

Gearing follows the circumference. 185/60R16 covers 1974.2 mm per revolution against 1932.1 mm for 195/60R15, so it needs -17.8 fewer revolutions per mile. At a fixed road speed the engine speed drops or rises by the same 2.2% 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 185/60R16 clear after 195/60R15? What to check before fitting

Clearance is the check the numbers cannot do for you. 185/60R16 is taller and 10 mm narrower than 195/60R15, so check the wheel arches, the suspension components and the steering lock: turn the wheel fully in both directions and check for contact, and check again with the suspension compressed and the car loaded as it will actually be used. A size that clears when the car is stationary and unloaded can still rub over a bump or at full lock. This page does not claim that 185/60R16 clears your car, and no diameter table can — only a physical check on your vehicle can confirm it. Also confirm the load index and speed rating of 185/60R16 meet what your placard asks for, and that the 16-inch rim suits the car.

Which size suits which priority: 195/60R15 or 185/60R16

Choose on the basis of what matters to you, not on the headline alone. If ride comfort matters most, the sidewall change of -6.0 mm is the figure to weigh. If grip matters most, the width change of -10 mm is the one to weigh. If keeping the instruments accurate matters most, the diameter change of +2.2% is the one to weigh — and if it is outside the plus-or-minus 3% guideline, ask about recalibration. And if the answer to the clearance check is uncertain, that outranks all three: a tyre that rubs is not a viable option at any percentage. That is the point this page works through for 195/60r15 vs 185/60r16.

Related 195/60R15 vs 185/60R16 comparisons and tools

Frequently asked questions

What is the diameter difference between 195/60R15 and 185/60R16?

185/60R16 is +13.4 mm (+2.2%) larger in diameter than 195/60R15: 628.4 mm against 615.0 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 185/60R16 instead of 195/60R15?

The error follows the diameter ratio, +2.2%. At an indicated 30 mph the true speed would be 30.7 mph, at 50 mph indicated it would be 51.1 mph, and at 70 mph indicated it would be 71.5 mph. The full table in both directions is in the speedometer section above.

Is 185/60R16 wider than 195/60R15, and does that matter?

No — 185/60R16 is 185 mm wide against 195 mm for 195/60R15, a difference of -10 mm. A narrower tyre generally gives less rolling resistance and can behave better in standing water, with slightly less dry grip. Width also affects clearance, so check the arches and suspension at full lock.

Will 185/60R16 fit my car if 195/60R15 fits?

Not necessarily. 185/60R16 is taller by 13.4 mm and 10 mm narrower, and it needs a 16-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, 195/60R15 or 185/60R16?

Neither is better in general — it depends on what you want. 185/60R16 has a -6.0 mm sidewall difference, a -10 mm width difference and a +2.2% 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.