Aircon advice

[benchph1]

you may have the same vehicle model but im sure you do not use your vehicles the same way.
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1.
yes the cabin will be cooler if you use both front and rear aircon at the same time even if you are alone. but this is also translates to more fuel consumption. = less fuel mileage.

2. have the rear a/c checked too. just tell them not to touch the vents as your friend said. it maybe dirty already and needs cleaning

3. harap ng right fender, i assume its in the engine bay. air filter?