175/65R13 vs 165/65R14: Tyre Size Comparison, Diameter Difference & Speedometer Effect

If you are choosing between 175/65R13 and 165/65R14, the first question is how far apart they really are. 165/65R14 is the taller tyre: its diameter is 570.1 mm against 557.7 mm, +12.4 mm (+2.2%) larger. The sidewall goes from 113.8 mm to 107.2 mm (-6.6 mm), the circumference from 1752.1 mm to 1791.0 mm, and the revs per mile from 918.5 to 898.6. 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.

On this page, 175/65r13 vs 165/65r14 is 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 +2.2% 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.

175/65R13 vs 165/65R14 side by side

Measurement 175/65R13 165/65R14 Difference
Overall diameter 557.7 mm (22.0 in) 570.1 mm (22.4 in) +12.4 mm (+2.2%)
Sidewall height 113.8 mm 107.2 mm -6.6 mm
Circumference 1752.1 mm 1791.0 mm +38.9 mm
Revolutions per mile 918.5 898.6 -19.9
Section width 175 mm 165 mm -10 mm
Rim diameter 13 in 14 in +1 in

Diameter difference between 175/65R13 and 165/65R14: +12.4 mm (+2.2%)

Put the percentage in context. The plus-or-minus 3% guideline exists because small diameter changes produce small speedometer errors, and this change is +2.2%, which is inside that band. In revs per mile the shift is -19.9 (918.5 to 898.6), and in circumference it is +38.9 mm per turn. Those are not abstract figures: every mile you drive, the car covers +38.9 mm more or less per wheel revolution than the instruments expect, and the gap accumulates exactly like interest.

Speedometer error: 175/65R13 to 165/65R14 and back

The maths is a single ratio. 165/65R14 over 175/65R13 is 1.022, so every indicated speed after the swap is multiplied by that number to get the true speed: 30 becomes 30.7, 50 becomes 51.1 and 70 becomes 71.6 mph. In the reverse direction the ratio is 0.978, so 70 mph indicated is 68.5 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 165/65R14 (from 175/65R13) Actual speed fitting 175/65R13 (from 165/65R14)
30 mph 30.7 mph 29.3 mph
50 mph 51.1 mph 48.9 mph
70 mph 71.6 mph 68.5 mph

Sidewall height and ride comfort: 175/65R13 vs 165/65R14

Sidewall height moves by -6.6 mm between these two sizes (113.8 mm to 107.2 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 65%.

Width, grip and fuel use: 175/65R13 vs 165/65R14

Width changes by -10 mm, from 175 mm to 165 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.

Revolutions per mile and gearing: 175/65R13 vs 165/65R14

The revs-per-mile figures (918.5 for 175/65R13, 898.6 for 165/65R14) describe the gearing effect. 165/65R14 turns -19.9 fewer times per mile, so at any given road speed the engine turns slightly slower with 165/65R14 fitted — the gearing is effectively longer. That can make cruising a touch more relaxed and can trim fuel use slightly, but it also means slightly less acceleration from the same throttle opening, because each gear is effectively taller. The change is 2.2% either way, so the effect on everyday driving is subtle rather than transformative.

Will 165/65R14 clear after 175/65R13? What to check before fitting

Whether 165/65R14 physically fits is a question for your car, not for this table. The numbers say it is taller by 12.4 mm and 10 mm narrower, 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: 175/65R13 or 165/65R14

Weigh the four effects separately. Sidewall (-6.6 mm) for comfort. Width (-10 mm) for grip and rolling resistance. Diameter (+2.2%) 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 175/65R13 vs 165/65R14 comparisons and tools

Frequently asked questions

What is the diameter difference between 175/65R13 and 165/65R14?

165/65R14 is +12.4 mm (+2.2%) larger in diameter than 175/65R13: 570.1 mm against 557.7 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 165/65R14 instead of 175/65R13?

Taking 175/65r13 vs 165/65r14 as the case in point: 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 71.6 mph. The full table in both directions is in the speedometer section above.

Is 165/65R14 wider than 175/65R13, and does that matter?

No — 165/65R14 is 165 mm wide against 175 mm for 175/65R13, 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 165/65R14 fit my car if 175/65R13 fits?

Not necessarily. 165/65R14 is taller by 12.4 mm and 10 mm narrower, 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, 175/65R13 or 165/65R14?

Neither is better in general — it depends on what you want. 165/65R14 has a -6.6 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.