@ all those that did the fuel pump mod

[Rob5464]

I will be doing this on the 3.0 when its rebuilt. After-market temperature gauge will be fitted beforehand.

Nevermind what Toyota dicided, most TD engines run lean standard. But I can only speculate why.

[Apache]

most TD engines run lean standard. But I can only speculate why.

Because more fuel = more heat in a diesel engine. The opposite of a petrol engine.

[Rob5464]

Because more fuel = more heat in a diesel engine. The opposite of a petrol engine.

This is true but when designing the engine, why not make it run at its optimum to start with, cooling system included.

[yoshie]

This is true but when designing the engine, why not make it run at its optimum to start with, cooling system included.

Depends on your definition of optimum, single run drag engine, 8 race F1 engine or family saloon turning 50mpg and good for 200k mile.

Consider;
Reliability
Economy
Cost
Ease of production

Nothing much wrong with the cooling system when compared with like for like. Average 15years old 130k and needing a new head is not to shabby a performance.