HDi Running Temperature

[JJtheHITMAN]

The combustion process of petrol engines burn alot faster and initially hotter than what a hdi engine would, diesel engines create alot less excess energy, using half the amount of fuel at a lower engine speed than an equivalent cc petrol engine. After reading through the above im sitting on the fence, i would say a fmic would effect running temps but only on warm up, once at optimum operating temp and load i wouldn't think you would notice. So (imo) you are both correct. Thats me playing it safe LOL