The compression ratio of the 1999 Toyota Supra’s 2JZ-GTE engine was 8.5:1.
Compression ratio compares the cylinder’s total volume when the piston is at the bottom of its stroke with the remaining volume when it reaches the top. An 8.5:1 ratio is relatively low for a naturally aspirated engine, but it suited the 2JZ-GTE’s twin-turbocharged design by leaving more margin against detonation under boost.
The 2JZ-GTE was a 2,997 cc inline-six with an 86.0 mm bore and 86.0 mm stroke. In the 1999 Japanese-market Supra RZ, Toyota paired it with twin turbochargers and rated it at 280 PS. The engine’s iron block, strong crankshaft and six-cylinder layout helped give the Supra its famous tuning reputation.
A common mix-up is confusing the turbocharged 2JZ-GTE with the naturally aspirated 2JZ-GE, which generally used a higher compression ratio. The figure also applies to the engine specification, not a universal ratio for every modified or aftermarket 2JZ build.