Toyota SZ (1SZ / 2SZ)

Toyota's smallest fours — the 1.0 1SZ, 1.3 2SZ and 1.5 3SZ — in the Yaris, Echo, Platz and, badged Daihatsu, a long list of others.

⚑ The 1.0 1SZ-FE is a FOUR-cylinder, not a three, which catches people out because every other one-litre engine in this catalogue has three. An owner told their car has a three-cylinder has been told about the 1KR that replaced it, which is a different engine in the same model.

It is chain-driven and port-injected, so there is no belt to schedule and no direct-injection carbon to expect.

Its complaints are the small-engine set: a carboned throttle body giving a hunting idle, ignition coils failing one at a time, and a coolant temperature sensor that ruins economy without setting anything anybody notices. Very few of these are worth an expensive repair, which is usually what decides the outcome.