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Auto repair Q&A: Oil’s well that runs well

I thought modern engines were not supposed to use any oil. My 2008 GMC pickup with the 5.0-litre V-8 is going through a quart every 8,000-10,000 km. My dealer claims that is not of concern. – Rick, Alexandria, Ont.

That might be a bit on the wrong side of the coin but I don't think it's worthy of worry.

The "small block" GM V-8 is one of the most reliable, long-lived and popular engines in history. There are literally millions in use and they are built at a variety of locations. If you don't see any sign of leaks on your driveway or after a careful look under the hood and from beneath when on a hoist for a oil change, it likely means the engine is using a little oil in the regular course of events.

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Engines are assembled under a set of acceptable tolerances and perhaps yours is near one side of those tolerances. The important thing to watch for is any change in the pattern of oil use. You don't say how many kilometres are on your truck, but I assume it to be less than 100,000 km judging by the age. If the oil starts disappearing more quickly that might be a sign of developing problems.

At any rate, be sure to keep your dealer informed of the situation in case there are any questions about warranty or repair. It is always helpful to have a paper (or hard drive) trail.


My Oldsmobile dealer says that General Motors is using a new type of oil that is exclusive to them. He tells me I should change over to this oil and that it will cost me a little more to do so. I have been getting my oil changed at a local shop for decades rather than driving into the city where the dealer is located. Am I required to go to the extra expense and time of having the new oil from the dealer? – Ian in Fisher Branch, Man.

There are a couple of issues here. Firstly, that you refer to the dealer as an Oldsmobile dealer tells me you don't go there often. General Motors stopped making Oldsmobiles a few years back and there have not been any Oldsmobile dealers for some time, having predeceased Pontiac and Buick dealerships.

You are quite safe to continue using your local shop to get your oil changes done as long as they use approved oils and you keep a record of the date and mileage when the change was performed.

Like all manufacturers GM constantly conducts tests on its engines with an eye to maximizing life and, more recently, with respect to the environment and new legislation. GM is filling it engines at the factories with a new generation of motor oils designated SN, GF-5 or Dexos1. These oils are designed to provide not only greater protection from wear, but better fuel mileage thanks to reduced friction and drag.

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The new oil takes the place of the previous-generation designated SM or GF-4 and requires change less frequently. The new oils can be used in older vehicles.

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