I have a 2017 Toyota Fortuner with about 118,000 kilometers, and something small has been bothering me for the last ten days. When the AC is on and I pull away from a stop, the car feels a bit heavier and slower, and the gear change seems to come a little later than usual. When I turn the AC off, it feels smoother. My sister says all cars lose some power with the AC, and she is probably right, but my neighbour who knows cars well told me not to ignore it. He said I should learn the top gearbox failure symptoms every Sharjah driver should know, because small changes like this can be an early sign if they get worse. I read a page about gearbox warning signs online one evening, just to understand the basics, and it talked about delays, slipping, noises and leaks in easy words. It helped, but it did not say much about changes that only happen with the AC on. So here are my questions for people who know more. Is it normal for an automatic to shift later when the AC compressor is working, or is that a sign something is wrong? How much power does an AC really take from the engine on a car this size? Could the problem be the engine instead of the gearbox, like old spark plugs or a dirty throttle part? Another thing is how to tell the difference. Is there a simple test, like driving the same road with the AC on and off and comparing? I also wonder about the fluid. The car has never had a gearbox oil change that I know of, so should I check it now or wait until I notice something stronger? Does a scan show early problems even when no warning light is on? How much does a basic check cost, and how long does it take? I park outside in the sun and sit in slow traffic almost every afternoon, so maybe that adds to it. The car is my daily drive for work and the school run, so I cannot leave it for many days. If you had the same feeling with the AC on, please tell me what the cause was, what you paid, and if it went away. Even a small tip will help me a lot. Thanks for reading, and sorry for the long message.