Answers to your car questions

QUESTION

Hi Dennis, I’m a long-time reader of your columns in the Spectator but I have been reluctant to ask this question about engine oil because it will likely seem rather repetitious. When I first got a car and began driving in 1963, I always used SAE 30 oil, whether it was an older car with high mileage or a somewhat newer model. When the oil terminology changed to, for instance 10W30, that’s what I used. In 2008 I bought, from a reputable dealer, a 2004 Mazda 3 with about 144,000 kms showing on the odometer. The dealer did some minor repairs along with an oil and filter change and new brakes all around. No complaints at all about the dealership or the car. Since I don’t drive a great deal, I generally do an oil and filter change once a year originally using 10W30 oil but a couple of years ago, I switched to synthetic 10W30. However, the cap on the oil-fill pipe suggests the use of 5W20. I had stuck with the 10W30 partially out of habit and partially because the car now has approximately 266,000 kms on it, figuring that the heavier oil might be a better choice due to engine wear. My question is: Do you think it is a good idea to change to 5W20 or should I simply stick with 10W30? The car runs well and starts easily in cold weather although the mpg is not as good as it was originally. I attribute that to the age of the car. My hope is to get at least another five or six years out of the car, as it’s a blast to drive and the least-tiring car that I’ve ever driven (eighteen hours from Charlottetown to home in Grimsby with stops only for gas). Thanks for any thoughts or suggestions that you’re able to offer.

Cheers, Wayne from Grimsby

ANSWER

The right choice was to stick to the 10W30 oil and even a better choice was to switch to synthetic oil. In order to squeeze out as much mileage as they could, the car manufacturers felt that the 5W20 oil would help with that goal. The 5W20 oil would also need to be changed more often because any type of contamination would quickly break down the 5W20 oil and it would quickly lose its ability to properly lubricate the internal parts of the engine. Now, if you were living up in the Yukon or some other freezing part of the world, you would need to use the 5W20 oil, just to be able to start your vehicle. Most new car manufacturers and dealers use the 5W20 oil and that is okay when the engine is new but I like the 10W30 synthetic oil when the engine has reached one hundred thousand kilometres.

QUESTION

Hi Dennis. First of all, I’d like to thank you for your interesting and no-nonsense columns, which I look forward to reading each week in the Waterloo Region Record. Some of the recent advice and debates over oil changes has pushed me to ask you for your honest opinion on what you see as the required frequency for a very specific situation. When I retired almost ten years ago, my wife had been secretly setting aside money for twenty years to purchase a 2012 Jaguar XK convertible for me as a retirement gift. We only use the vehicle for the occasional outing for an out of town lunch and only when the weather is perfect. These journeys are usually on rural highways and close to an hour of travel time each way. Since purchase, I have faithfully had the oil changed at our local Jaguar dealer each fall, before storing the car for the winter. Over this time, I have had the oil changed ten times and as of today, I have put just over 12,000 km’s on the car so an average of 1200 kms between changes (a declining average). Oil changes at the dealer are now nearing $500 and I am wondering if it’s really necessary to keep doing this each year. The amount of use has been declining each year as well. This year, I am still on the same tank of fuel (and stabilizer) that I had put in last fall before storing. So, specifically, if I used the car for 3 or 4 outings this year, covering less than 500 kms, do I really need to part with $500 to replace what I suspect is still “new oil” with slightly newer oil? As I mentioned earlier, your honest opinion in this particular circumstance would really be appreciated.

Thank you and I look forward to hearing back from you.

Glenn from Kitchener

ANSWER

I have had this conversation with many oil companies and I guess that I have to believe what they are telling me about why time matters, when it comes to oil deterioration over time verses mileage. Motor oil is made up of many ingredients for better protection under extreme conditions. The possibility of these different additives could over time cause the oil to separate, much like the ethanol in gas will over time separate from the gas. That is why you will find an expiration date on a can of oil that you purchase. Contrary to what some believe, motor oil can break down in an engine over time by losing its viscosity and its efficiency to maintain proper lubrication to the internal parts of the engine. As this is taking place, the chemical configuration of the oil is altered and it becomes contaminated. Short daily four to five kilometre trips per day also add to the loss of proper oil lubrication as a result of condensation contamination of the oil. Your car is one that you do not want to have an oil contamination problem. I would sit down with the service manager at the dealership to discuss how you can get the cost down such as possibly only changing the oil filter once on two oil changes.

To my readers: Please indicate the town, city or village that you live in. Be advised that not all emails can be answered. Send your questions (including address) by email to: dennis.osullivan@cogeco.ca