1999 BMW 740i — Sport Package

The 1999 BMW 740i Sport Package shipped with 2 different factory tire sizes, depending on the wheel package it left the factory with (this can also reflect a staggered front/rear setup). Check your tire sidewall or door placard to confirm which one applies to your vehicle.

This trim shipped with more than one tire size (staggered fitment, front/rear, or optional wheel package). Confirm which one matches your vehicle by checking your tire sidewall or door placard.

235/50R18 (Front)

Section width235 mm
Aspect ratio (sidewall height)50% (117.5 mm)
Rim diameter18"
Overall tire diameter~27.3"
Revolutions per mile~740

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255/45R18 (Rear)

Section width255 mm
Aspect ratio (sidewall height)45% (114.8 mm)
Rim diameter18"
Overall tire diameter~27"
Revolutions per mile~746

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What this size means for your BMW 740i

On the 1999 BMW 740i Sport Package, the factory 235/50R18 measures about 27.3″ in overall diameter with a 117.5 mm (4.6″) sidewall, and completes roughly 740 revolutions per mile. Its 50-series aspect ratio gives a balanced everyday-passenger profile — enough sidewall to soak up road shock while keeping steering response crisp. In tire terms it is a passenger (P-metric / Euro-metric) size.

This is a staggered setup: the front axle runs 235/50R18 and the rear runs 255/45R18. The two sizes are not interchangeable, so order each for its correct axle and don't rotate front-to-rear.

On a vehicle of this age, the BMW 740i may have been refitted with a slightly different replacement size somewhere in its life, so check the current sidewall — not just the factory spec — before buying.

Other 1999 BMW 740i trims

BMW 740i tire sizes by year

See every BMW 740i year & trim →

How to read a tire size

A tire size like 225/45R17 breaks down into three parts: the first number is the section width in millimeters (the tire's width from sidewall to sidewall), the second is the aspect ratio — the sidewall's height as a percentage of that width — and the number after the "R" is the rim diameter in inches. A letter prefix (P or LT) indicates Passenger or Light Truck construction; its absence usually means Euro-metric sizing.

Some trucks and off-road tires instead use "flotation" sizing, like 37X12.50R17 — here the numbers are the tire's overall diameter and width in inches directly, with the rim diameter last.

Always verify against the tire information placard on your driver's-side door jamb or your owner's manual before purchasing — tire size can vary by factory option package even within the same trim.