Why do Diesels supposedly last longer than petrol engines ?

[camper48]

hi all. son has a petrol gas Datsun has 400000 on clock it gets treated like Shit but is serviced regularly
enjoy 4b

[Ratbag]

There are quite a number of people on Subaru fora who have over 400,000 kms on their original  petrol donks. Specifically the EJ series engines, but others as well. Many of these are well looked after, but used hard.

My '93 Subaru Impreza had around done 236,000 kms when I traded it in. During a 4,500 km roundtrip to Brisbane in 2011, it used no measurable quantity of oil or water and the ambient temperature was around the high thirties to mid forties on most travelling days. My right foot is far heavier than my left  . For much of its life, I drive it like I stole it, as the car was heavy, the engine gutless and the gearing and tune all wrong, I spent a lot of time revving its rings off ... It had an EJ-18 engine (1800 cc), and weighed nearly 1200 Kgs tare. The only engine repair in its life with me was a new water pump at around 210K kms.

Ask someone who has had to replace their diesel particulate filter for around $4000 about the reliability of what I call "consumer diesels" (to distinguish them from things like the 3 cylinder GM diesels in our farm tractors).

It is my understanding that the DPF in modern heavy diesels is separate from the catalytic converter, and is designed to be easily removable and cleaned. With consumer diesels they are part of the catalytic converter, and are a throw away item.

[Marschy]

I would have thought that the longevity of most modern diesels would still be better than modern aluminium block engined petrol engines? A well maintained cast iron block engine can be repaired unlike a modern aluminium block engine. The aluminium block engines, no matter how well maintained will generally have a shorter life span due to corrosion in the water jackets eventually killing the block.

Just look at engines from vintage cars as a good example, how many of them are able to be totally rebuilt using the original block and head when there are aluminium components, like the head? Not many, unless original parts are available.

[slydar]

However this is old school diesels modern CRD is now as complex as petrol with the same lifespan

yep - 'when I was a lad' diesels didn't have any of this - or glow plugs - diesels were diesels. one tugboat I worked on went for years flawlessly - but when they go, they go.

I also find diesel driver tend to be more sedate (did they have any choice...?) - I drive my petrol pajero like  a diesel and it's still pretty much much as it was when I bought it barr the traditional mitsubishi worn valve guides- first timing belt was changed at 270000km and only then because the water pump went

[speewa158]

Was it an NL 3.5 l petrol 

[jeeps]

My wife's 2008 lancer has done about 260,000 without any problems, we've had it since new. Regular servicing every 15-20k. My petrol jeep has done 180,00klm without a hiccup though it's a cast iron pushrod, with regular servicing. Diesel or petrol look after them and they'll look after you, though i probably wouldn't buy a modern diesel as i've had such good runs from petrol.

cheers

[slydar]

Was it an NL 3.5 l petrol 

why, yes it is - how did you know...?

(smokes and clatters back out again...)

[Brett B]

I loved the old Detriot Diesel  but they liked to drink the fuel 

[speewa158]

Brett B
 The Old DD  did do the job  , & yes sucked the juice  , but they did the job     

[markymark]

Our 3.4L petrol 90 series Prado has over 340,000km on it and going just as strong as the day we got it (@140,000km), serviced every 10,000km and only takes around 5L of oil (I think the diesel is double that amount and needs it every 5,000km). Our mechanic says that's nothing as another customers 90 has over 500,000km on his and it too is running fine. They don't have the low-down torque of a TD although I think the 4.0L in the 120 Series is pretty torquey at low revs.