luxury1

The LS is good about retaining heat in the winter and I am really grateful for this. I get out, go to dinner and when I arrive back to the car there is still a good amount of heat in the engine to warm the car quicker. My RX on the other hand does not do this. If you turn off the car the engine loses its heat almost immediately.

What technology allows for this in the LS that the RX is missing?

Johnny

Much larger engine + Transmission (mass) = Greater heat retention

Heat takes longer to dissipate compared to smaller engines. Nowadays, engines contain more aluminum than in the past (cast iron). Older engines therefore dissipated heat even slower, but they also took longer to warm up, unlike today.

luxury1

Is this all that it is because my V6 3 series, 5 series and E Class were all very good at heat retention so I have to think that it is something else (they were all V6 engines). My Range Rover is also but that is a V8.

Johnny

I forgot to mention cabin insulation. The LS has a lot of noise abatement foam and padding enveloping the cabin. Invariably, this also keeps the interior warm long after the occupants egress.

Nospinzone

I haven't noticed the heat retention yet because it just got cold here in the Boston area (and then it snowed and my baby doesn't go out in the snow).

I'm just guessing, but perhaps the shroud that covers the engine helps retain some heat.

zzzzdoc

This is a better example of an engine retaining heat.

http://www.talklambo.com/showthread.php?t=2627

350Dave

I used to whip up a mean souffle at 70 MPH for about 90 minutes

encore888

How about the effect of turning on the heater A/C? Or heated seats? Takes longer I guess?

Nextourer

It's possible the LS' engine bay is tighly packed whereas the RX, being an SUV, might have a larger engine bay than is necessary allowing air to flow through it (say if it was windy) and cool it faster. Or perhaps the engine is exposed to the ambient air, whereas the LS has a few other things "insulating it" and that the engine is surrounded by other items.