After years of owning my 2007 Tarago, I only just found out that if you turn the A/C off just before shutting off the engine, when you turn the engine back on again with the A/C remaining off, you get sluggish engine response and bad fuel economy, probably because the A/C compressor is still partially engaged to the engine, even though the A/C is switched off.
It seems as though that if you shut the engine off too soon after shutting off the A/C, the A/C compressor is not able to fully disengaged from the engine. So when you turn the engine back on again, the A/C compressor still remains partially engaged and continues to be a drag on the engine, despite the A/C button being off, resulting in poorer fuel economy.
For years, I couldn't understand why my Tarago was so sluggish despite the A/C not being used and the fuel economy wasn't good either, getting a fair bit higher than the 10L/100Km quoted by online car reviewers. Then one time after being frustrated with the sluggish engine response, I tried turning the A/C on momentarily and then off again, and voila, the engine was spritely and responsive again, and fuel economy matched with online reviews.
Something for people to try if you find your Tarago is sluggish and giving poor fuel economy.
Only works for 2006 Taragos (ACR50/GSR50) onwards though as these used the clutchless variable compression compressors