Ford Fiesta Mark 7: 1.6 Duratec Petrol vs 1.6 TDCi PSA/Ford?

Hi so to answer this one has to be fair which is impossible given thus between diesel and petrol. you have identified the difference between being british or american.

diesel engines last longer and need to be driven hard to get any real performance when compared to a petrol engine. so sadly todays cars have this built in mileage limit of 100k miles for a petrol engine when compared to a diesel engine of say 150 k miles.

then you need to consider how it has been driven in the past. having own a couple of big diesels which where both driven by those with no idea the engines where sluggish. it takes several thousand miles to get them loosened up. unlike a petrol car which when it has done over 100k miles is near to the end of it's life and rattles a lot.

The diesel is the superior engine. The PSA group know how to make reliable, powerful and refined diesels. Which is why Ford collaborated with them. All diesels outlast petrols by a huge margin because apart from being a stronger engine the fuel acts as an additional lubricant to the pistons and valves. Also the diesel version will have greater torque and be a more relaxed drive in traffic. Mpg will be in the 60s. The only downside is that they are more expensive than petrols. But in this respect you get what you pay for.

The BEST engine is the one that came in the car from the factory.