rx8 dx

Hi guys. When the car is inside the garage and we start the engine, it takes a couple of minutes for the temperature needle to go up to the middle mark. I don't go full force until the engine is warm enough. The question is , if I leave the car outside, temps around 90F, it takes seconds for the needle to go up to the middle point instead of minutes. Does having the car and engine warm from the sun compensate for those initial minutes of normal (inside garage,shade)minutes that the car is bypassing because is hot from the sun?. Is the car ready for WOT or is just a fake temperature and I should wait a couple of minutes ?
Thanks

mysql101

The coolant may be warmed up, but the engine still takes time to warm up. Give it 5-10 minutes before you start going over 4k rpms.

Gord96BRG

The coolant temperature is NOT a good indicator of when the engine is warm enough for WOT and high rpm operations. The reason is that coolant heats up and reaches its operating temperature much quicker than the oil and the metal engine components, and those temperatures are much more critical. Remember, the rotary engine is made of layers of aluminum and iron plates, which have different coefficients of expansion (they expand differently with temperature changes). The metal parts of the engine need to be fully warmed up before running hard, and that takes quite a few minutes longer than the coolant to reach. Once your coolant reaches operating temperature, I'd suggest waiting at least another 5 minutes before driving hard. That recommendation is based on watching the coolant temperature vs. oil temperature on my twin-turbo Audi, where it is easily seen how much longer the oil takes to warm up (oil temperature is a much better indicator of the engine reaching operating temperature).

Regards,
Gordon

rx8 dx

That makes a lot of sense. Always wondered about it. I was never going to WOT the car till I was sure about the mechanism of ambient temperature on the cold renesis.


Thanks

Vinnie

rx8 dx

So because of the metal expansion due to heat production, does the actual volume of the engine expands and have more space for the gases to expand producing more energy coming out of the engine? If so, is the 1308 cc based on a cold or hot engine?

Thanks

Vinnie