Synthetic oil, and warming up the car: Ask a Mechanic

Every week, we take your questions about what is going on under the hood of your vehicle and pose them to a knowledgeable mechanic in the Greater Toronto Area. In today’s column, we learn more about synthetic oil and whether you need to warm up your vehicle before driving in cold weather.

Dear Ask a Mechanic,

I have been hearing about synthetic oil versus conventional oil and was curious what synthetic oil actually is exactly and whether one is better for my engine than the other. Is synthetic oil better for the environment and how it is it disposed of? – Oil Conscious

Talha Qazi, owner of General Tech Automotive in North York, has been a licensed mechanic for the past nine years but first started learning the trade when he was 13 years old. While conventional oil is made from crude oil that has been refined and has additives and chemicals added to it, Qazi said synthetic oil is made in labs, has more additives and is a thinner liquid.

He said the type of oil needed in a car will depend on a vehicle’s engine; oil is used to prevent friction and wear, so an oil’s viscosity (essentially how it flows based on a number of factors) has an impact on how well it protects an engine’s parts.

At his shop, Qazi said he works mostly with synthetic oil because manufacturers have produced vehicles over the last few of years with engines that work with this type of oil. Qazi said owners should listen to their vehicle’s manufacture and what they recommend if they are confused about what oil to use.

He said synthetic oil lasts longer compared to conventional oil. Both are disposed of in the same way, he added, but synthetic oil is generally seen as being less harmful to the environment because it does not have to be changed as often.

Dear Ask a Mechanic,

When it was cold in February, my neighbour suggested it was wrong for me to just get into my car and drive it. He had seen me do it and said I should always wait for the car to warm up before I started driving. Is this really true? It seems wrong to just leave my car idling in the driveway. – Idle Thoughts

Imagine you’re waking up in the morning and you want to go for a jog. Before you head out the door, you will probably do some stretches to help avoid any injuries. Warming up your car before you drive follows the same principle, said Qazi, who recommended you let your car run for 30 or 40 seconds, if not a minute, before driving.

When you start your vehicle in the morning, the oil is at the bottom of the oil pan and has to be circulated through the engine to ensure it is lubricated, he said. “The oil is so thick; it has to warm up a little bit in order to become less viscous so it can travel through the engine faster,” Qazi said. This is important, he added, because it gives the friction modifiers in the oil time to coat the metal parts in the engine to help reduce wear.