Extra Engine Heat on starting Air Conditioner.

Do you mean that the engines are overheating, or merely running hotter than normal when using A/C?

Obviously the simply answer to running hotter than normal, but not actually overheating would be to run a Group IV/PAO synthetic oil. There would likely be a slight decrease in temperatures, and the oil would be able to take the heat much better. (I have no idea what brands are avalible to you, but Mobil 1, Redline, Amsoil, Royal Purple and others make such oils). Obviously, as you know, in very hot climates, heavy oil weights such as 15W40, 15W50, and even heavier are a good idea, and possibly even straight weights, a topic which Gurkha can better advise you on than I.

If the problem is actual overheating, or similar, you should simply sell your customers bigger, possibly aluminum radiators, and oil/transmission fluid coolers.


As a side note, if you have customers with air cooled or turbo engines, you should definitely try to sell them synthetic oils if possible, and in a heavier than normal weight.

Kamran,

I have been associated with Castrol in India for almost two decades. My experience is that in the sub-continent engines have two type of coolings systems (Heat exchangers).

The order type of cars were fitted with large and elaborate coolings systems (for engines), and largely water cooled and supported by a "big fan" permitting air cooling. As these are open systems and with a fair amount of leakage and evaporation of the water, system breakdown.These are no longer efficient.

Modern cars have a very compact and tightly looped engine cooling system. This is a closed system and uses a coolant in place of water. The coolant consists of a synthetic water soluble solution, which does not evaporate and runs on a closed system. This is very efficient and widely used in all types opf cars and other vehicles as well.

Hussam Adeni

Pakistan and India's northern portions near the Rajasthan and Baluchistan dessert tend to get really hot with temps touching and sometimes exceeding 50c. With conditions like that, the safest bet is what Abus suggests, use synthetics for gasoline engine, check coolant and replace them every three years and it is a good idea to let the heat off by opening the hood after a long drive. This way there is less chance of the heat soaking of electrical wires and other plastic parts. For diesels, synthetics can run really costly so I suggest using excellent CI-4 rated oils like Mobil-Delvac Super and Chevron's Delo 400 which is an ISOSYNTH and provides fantastic cost to performance ratio. The only thing with the diesel oil is that you have to change at 6 months or 6000 miles or sooner if driven under severe hot and dusty conditions. With today's cramped engine bay which is more on cost savings and aesthetics rather than functionality, heat build up is quite normal under the hood.

If still wandering to A/C load is rejected usually upstream of the radiator and thus loads the cooling system this way. Also the engine timing or the speed is increased to counter the comp load. All the compresser load is heat and underhood, indirectly heating engine. Also usually high outside temp when AC needed so harder to dump heat out. Even the blowers heat is dumped into the airstream. I would think they would be more concerned with the MPG loss than any heating issues, I have a large 4 cyl. (2.2l) that goes from 20/22 to 14/15 mpg with the AC on.