When comparing a 1. L engine to a 2. L engine, the primary difference lies in their displacement, which affects power output and fuel efficiency. The 1. L engine, being smaller, is generally more fuel-efficient and economical, making it ideal for daily commuting and city driving. The tried and tested VW Golf 1. TDI dominated with various power levels from 90 to 150 hp. These VW Golf TDI engines (ALH, AHF, ASZ) are considered the most reliable diesels of all Golf generations.Well, obviously the 2. Golf 1. TDI’s 120hp, quite a bit more so. Lots more torque too, which makes driving much more effortless.Engines between 1. With great fuel economy, having a 1. L engine means you won’t need to visit a petrol station as often. Litre Engines They’re still usually good on the fuel economy front, so you won’t have to pay too many visits to the petrol station if you mainly drive around town.