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Historically, there was only two or three popular motor-oil viscosities to choose from, and occasionally mixing them up rarely left any long-lasting negative side-effects. Transmission fluids were also fairly simple, consisting of only two popular fluids – Mercon or Dexron. All a technician had to do was pull the dipstick out of the engine or transmission and read what fluid type was required.

Contemporary dealer technicians have a parts department that they rely on to supply them with the correct fluid, so other than the occasional error, they have it pretty easy too.

Out in the independent world, where factory-level information can be difficult to access, the varieties and variations of fluid products can be a bit overwhelming, especially on newer vehicles. GM has its Dexo-specified oil products, European vehicles use all manner of oils with designates such as 502 or 504, and European diesels have another level of complexity, requiring oils with low sulfated ash, phoshorus and sulfur (SAPS) levels. Contemporary transmissions can be just as difficult when it comes to deciding on what fluid goes into it. Accidentally put a Dexro-based fluid in a continuously variable transmission (CVT) and disaster awaits.

Considering many cars now regularly consume oil, I get a fair number of queries about top-up oil alternatives.

If you own a vehicle that requires a specific oil, understanding the difference between 0W20 and 5W20 is simply not good enough anymore. Just in case these numbers are a mystery, the Society of Automotive Engineers (SAE) came up with a simple viscosity rating system. The preceding 0W or 5W is the low-temperature viscosity rating, with a lower number indicating a thinner oil when cold. The number after the W is the hot operating-temperature rating – once again, lower means thinner.

If your vehicle specifies 0W20, this is always going to be a synthetic-based oil. However, your owner’s manual will usually suggest an alternative that can be used in a pinch. Namely, one litre of 5W20 non-synthetic can be used on occasion. That being said, 0W20 is pretty common now and rarely can’t be found.

GM uses their own designated oil referred to as Dexos in the 5W30 synthetic grade, and GM specifies it must be used. However, once again, using a full synthetic 5W30 non-Dexos as an infrequent top-up is not going to do any harm. Just don’t make a habit out of it, especially during your warranty period. Remember, any motor oil is better than no oil when you find yourself in a desperate situation.

From there, we move on to the European-rated oils, and it gets confusing quickly. In addition to a simple viscosity rating like 5W40, there are also additional specifications that need to be met. For example, Volkswagen designated that long-life interval oils with a 501.00 thru 504.00 specification are most commonly used in their gas-powered engines, with each oil superseding the previous. Meaning you can typically use a 504-rated oil in an older 501-specified motor, but not the other way around. 505.00 thru to 507.00 oils are usually related to diesel engines with low SAPS requirements. These 500-series oils require extra attention being paid to your owner’s manuals, as repeatedly using the wrong oil will have negative consequences.

An equal amount of frustration can be had when dealing with transmission oils. Given that most people aren’t topping up their transmissions on a regular basis, we’ll leave transmission fluids for another day.

Your automotive questions, answered

Does GM offer an eight-year warranty on a catalytic converter in Ontario? I can’t find any documentation on this. I’m being told it is covered by some. My car is a 2014 Buick Encore with less than 70,000 km on it.

A response would be appreciated.


Craig A

I also came up empty-handed after spending a fair amount of time researching Canadian laws regarding catalytic convertors. In the U.S., it is laid out quite clearly. U.S. federal law states that catalytic converters and engine-control modules must be covered for eight years and/or 80,000 miles. Maybe some legal expert can chime in in the comments section if I’m incorrect, but as far as I can tell, no such actual law exists in Canada.

However, GM’s website states that specified major emission components are covered for eight years and 130,000 kilometers, which is not surprising, as it is approximately 80,000 miles. The problem is that it does not state what these emission components are.

Since I was having little luck taking a general route by looking up laws, I decided to download the owner’s manual and warranty booklet for your specific vehicle. Finally, I had some luck finding an answer. If you open your warranty booklet and head over to sections 27, 28 and 29 Emission Control Systems Warranty, their specified eight-year, 130,000-kilometre items are notated with an asterisk. Yes, catalytic converters have an asterisk beside them, which indicates to me that they are indeed covered.

Lou, my 2006 Audi has been parked in a heated garage with a full tank of gas for the past two years. Other than charging the battery, what do I need to do in order to safely start driving it again?


Barry C.

Two years is just long enough a duration that I would have a bit of concern but also not significant enough that we need to overthink this. The areas that will need attention related to storage are obviously the battery, along with the fluids, brakes and timing belt.

Brake fluid will need to be changed as it is hygroscopic and absorbs moisture. Most manufacturers require this fluid to be replaced at least once every two years regardless of actual distance driven. The remainder of the fluids will need an inspection. However, fluid inspection is a subjective experience, dependent on the person actually doing the inspection. I would recommend erring on the side of caution, replacing fluids that are questionable.

Your braking system may be the only area that holds a surprise. Should any brake pads have corroded and frozen to the brake rotor, you may be in for a bit of financial unpleasantry. A test drive will either yield a vehicle that self-clears the corrosion quickly or has a nasty vibration and noise that requires immediate servicing and possible brake-component replacement.

You haven’t indicated what model Audi you own, but should it be a model with a timing belt such as an A4, you need to check your history for timing-belt replacement. If you haven’t replaced this maintenance item yet, it needs to get done immediately as well.

Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail, placing “Lou’s Garage” in the subject line.

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