205 is the section width in millimetres, 55 is the aspect ratio (sidewall height as a percentage of width), R means radial construction, 16 is the rim diameter in inches, 91 is the load index and V is the speed rating. Paste the whole string into the "Read a marking" task and every segment is decoded with its value.

91 is the load index — per the reference table it corresponds to a maximum of 615 kg per tire. V is the speed rating, corresponding to a maximum of 240 km/h. Together they form the service description; a replacement tire should not go below the original in either value.

Overall diameter = rim diameter + 2 × sidewall height. For 205/55 R16 that is 16 × 25.4 = 406.4 mm plus 2 × (205 × 55%) = 225.5 mm, giving about 631.9 mm. The compare task uses this formula on both sizes and reports the percentage difference against the ±3% reference window.

XL (Extra Load, sometimes RF for reinforced) marks a reinforced construction that carries a higher load index than the standard-load version of the same size, at higher inflation pressure. The size segments read the same way; the XL suffix is reported as a note when decoding, and the load comparison still uses the printed load index.

No. The verdict only checks size-level rules — diameter window, load index and speed rating — against reference tables. It does not evaluate wheel width compatibility, body clearance, tread pattern, tire age or local regulations. Use it to verify a quote or ask better questions, and always confirm with the owner's manual and a professional before installation.

Metric markings like 205/55 R16 91V, including P / LT / T prefixes, ZR notation, dual load indexes (e.g. 120/116) and XL / RF suffixes. The reference tables cover load indexes 60-130 and speed symbols J-Y. Flotation sizes such as 31x10.50R15 and values outside these ranges are reported as not supported instead of being approximated.