2010 Nissan rogue (42,500 miles) When the a/c is on and I’m stopped in traffic, with my foot on the brake the car shudders. There are times I feel like it will stall. I’ve had it to the dealer several times and they’ve told me the compressor puts a lot of strain on the engine. I have been in many other vehicles small and large and do not notice this. Any insight or suggestions?

Dirty iac or map would be the most likely problem.

Is the engine RPM dropping when this happens? An idle speed that is even slightly low can cause the vehicle to shudder a bit.

Offhand, I agree with the IAC valve issue and will also add that the radiator cooling fans should be operating when the A/C is on. If not, that could also cause idle issues.

The compressor puts a strain on the engine but they all do no matter the make of car. The idle speed is controlled by the ECM (computer) through the IAC valve and the strain is compensated for electronically by elevating the idle speed a bit.