TreadIndexTire sizes converted, compared, and checked against your fenders.

What does 99V mean on a tire?

Load index 99 = 1,709 lb per tire
1,709lb
V means the tire is rated to 149 mph · four of these carry 6,836 lb
Load index 99 = 1,709 lb per tire1,709 lbLoad per tire6,836 lbAll four tires
Load per tire775 kg — index 99 on the ISO scale1,709lb
All four tiresthe ceiling for vehicle plus everything in it, not a target6,836lb
Speed rating V240 km/h — sports cars and performance sedans149mph
Next index up (100)55 lb more per tire1,764lb
Next index down (98)56 lb less per tire — do not fit this if your door label says 991,653lb

Notes

  • **99V means two separate things.** 99 is the load index: this tire carries **1,709 lb** on its own, at the pressure printed on the sidewall. V is the speed rating: the tire is built to hold together at **149 mph**. The two numbers are unrelated — a high load index says nothing about speed, and vice versa.
  • **The load figure is per tire, not per vehicle.** Four 99-rated tires carry 6,836 lb between them, and that has to cover the car, the fuel, the passengers and whatever is in the boot. Compare it against the gross vehicle weight rating on the door jamb, not against the kerb weight in the brochure.
  • **Never fit a lower index than the door label.** The placard inside the driver's door gives the minimum load index the manufacturer signed off on. Going below it is the one substitution in tire fitment that has no upside — it saves a few dollars and removes margin from the only four patches of rubber holding the car down.
  • **A speed rating is a ceiling, not a recommendation.** V at 149 mph assumes correct pressure, correct load and a tire in good condition. Under-inflation is what actually destroys tires at speed, and it does it well below the rated number.
  • Both markings sit at the end of the size, after the diameter: a tire marked 225/45R17 99V is a 225-wide, 45-series, 17-inch tire rated 1,709 lb and 149 mph.

99V is two answers, not one

99 is the load index: this tire carries 1,709 lb on its own. V is the speed rating: the tire is built to hold together at 149 mph.

The two are unrelated. A high load index says nothing about speed, and a fast tire is not automatically a strong one.

The load figure is per tire

Four 99-rated tires carry 6,836 lb between them — and that has to cover the car, the fuel, the passengers and everything in the boot.

Compare it against the gross vehicle weight rating on the door jamb, not the kerb weight in the brochure. The two numbers differ by several hundred pounds on most cars, and the brochure is the one that flatters.

Never fit a lower index than the door label

The placard inside the driver's door gives the minimum load index the manufacturer signed off on.

Going below it is the one substitution in tire fitment with no upside: it saves a few dollars and takes margin out of the only four patches of rubber holding the car on the road.

A speed rating is a ceiling, not a recommendation

V = 149 mph (240 km/h) assumes correct pressure, correct load and a tire in good condition.

Under-inflation is what actually destroys tires at speed, and it does it well below the rated number.

Where to find it on the sidewall

Both markings sit at the end of the size, after the diameter — a tire marked 225/45R17 99V is a 225-wide, 45-series, 17-inch tire rated 1,709 lb and 149 mph.

Nearby sizes

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