THE TT quattro's 1.8-litre, twin-camshaft, 20-valve engine has an unusually high compression ratio of 8.9:1, made possible by toughening up the internals including pistons, connecting rods and big end bearings. Additionally, over the regular 1.8-litre turbo engine used in the two-wheel drive version, it gets a bigger turbocharger with new exhaust and intake manifolds. Two air-to-air intercoolers are also part of the strategy enabling the high compression ratio because they keep intake gas temperatures relatively low to avoid detonation or "pinging". The flywheel and clutch are also beefed up to handle the 165kW.