car maintenance myths, and what is actually true

most car care advice starts with something that was once true, and then keeps getting repeated after it stops being true. here are the ones we hear most.

"change the oil every 5,000 kilometres"

true in 1985. modern synthetic oil in a modern engine goes considerably further, and your manufacturer publishes the number. changing early wastes money and oil.

the genuine exception is severe service: short trips, extreme cold, dust, towing. that is a shorter interval, and most Ontario drivers are closer to it than they think.

"premium fuel is better for your engine"

only if your engine requires it. octane is resistance to knock, not quality or energy. in an engine designed for regular, premium buys you nothing at all.

in an engine that requires premium, using regular is a real problem, and "it seems to run fine" is not evidence, because the computer is pulling timing to protect the engine and quietly costing you power and economy.

"you need to warm the car up before driving"

not for more than about thirty seconds. modern engines reach operating temperature faster under gentle load than at idle, and long idling in cold weather washes fuel past the rings.

drive gently for the first few minutes instead. that is warming it up.

"dealer servicing is required to keep the warranty"

not in Canada. you may have work done wherever you like, provided the correct parts and specifications are used and you keep the records. keep the invoices.

"flushing the transmission causes failure"

the half-truth that will not die. flushing a neglected transmission at high mileage sometimes precedes a failure, because it was already failing and the fluid change did not cause it.

fluid changed on schedule, with the correct specification, is straightforwardly good for a transmission.

"that noise will probably go away"

it will not. noises are the cheapest diagnostic information you will ever get, and they are always cheaper to investigate than to wait out.

what we do with any of this

tell you which of it applies to your vehicle. some of these myths cost people money doing unnecessary work, and some cost far more by skipping necessary work, and which is which depends on the car in front of us.