2009 Chevrolet Avalanche — LTZ
The 2009 Chevrolet Avalanche LTZ came from the factory equipped with 275/55R20 tires. If your vehicle has since been fitted with aftermarket or upsized wheels, your actual tire size may no longer match this factory spec — always confirm against your door placard before buying.
275/55R20
| Section width | 275 mm |
|---|---|
| Aspect ratio (sidewall height) | 55% (151.3 mm) |
| Rim diameter | 20" |
| Overall tire diameter | ~31.9" |
| Revolutions per mile | ~632 |
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What this size means for your Chevrolet Avalanche
On the 2009 Chevrolet Avalanche LTZ, the factory 275/55R20 measures about 31.9″ in overall diameter with a 151.3 mm (6″) sidewall, and completes roughly 632 revolutions per mile. Its 55-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 large-diameter fitment.
On a vehicle of this age, the Chevrolet Avalanche 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 2009 Chevrolet Avalanche trims
Chevrolet Avalanche tire sizes by year
- 2013 Chevrolet Avalanche 265/70R17 / 275/55R20
- 2012 Chevrolet Avalanche 265/70R17 / 275/55R20
- 2011 Chevrolet Avalanche 265/70R17 / 275/55R20
- 2010 Chevrolet Avalanche 265/70R17 / 275/55R20
- 2008 Chevrolet Avalanche 265/70R17
- 2007 Chevrolet Avalanche 265/70R17
- 2006 Chevrolet Avalanche 245/75R16
- 2005 Chevrolet Avalanche 245/75R16
- 2004 Chevrolet Avalanche 245/75R16
- 2003 Chevrolet Avalanche 245/75R16
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.