Re higher torque: wife's car is still on original clutch after the 300k miles, no major components have been changed
Apart from the compression ratio,
Yea, apart from the higher compression they have an easier life than a petrol engine.
Dirty derv' s
the oil soot loading causing 3rd body abrasion,
the high soot content EGR that blocks EGR valves,
intake manifolds and (with low pressure EGR) causes acids,
water and soot to condense in the intercooler
The (for a given emission level) more complicated aftertreatment
higher torque transmission
Higher vehicle weight
yes, they have a much easier life
Not sure it has an intercooler, but the exhaust is original, so acids can't be too bad? Old model I know
Re soot etc, cleaned it out about 50k ago by accidentally filling it with petrol and driving c 150 miles on petrol ( car was almost empty when I put the petrol in, recovery man ( it ran ok but refused to start when I stopped) said the petrol will have cleaned it out
I'm sure. There's loads of empirical evidence of diesel engines outliving petrols.
No, there are a lot of higher mileage diesels than petrols. That doesn't mean they last longer, it means they are a better choice for high mileage driving. Very few people are picking petrols to drive 100+ miles a day. Don't confuse correlation for causation.
I guess we'll know in 10 years time when we all switch back to petrol...
My dad had a Saab 9-5 Griffin (GM Petrol V6) which he did nearly 300k miles in. Not sure whether it is still around these days as he got rid in 2012, but he then had a 9-3 Aero (same engine I think) which he did over 200k in, so maybe they are as reliable as diseasels