Last spring I visited the Natural Resources Canada website
http://oee.nrcan.gc.ca/transportatio...dex.cfm?attr=0 while searching for info on idling, block heaters, and the like. I came across this from the site:
"Inspect and replace the air filter in your car. A clogged air filter can reduce your gas mileage and cause higher emissions. Your air filter should be changed every 25,000 km (15,000 miles) or more often if you are in a dusty area."
"Change the oil and oil filter in your car. It will reduce damage to your engine and reduce fuel consumption. For Canadian road and climate conditions, the average time between oil changes should be every three months or 5000 km (3000 miles). Using oil with the label "Energy Conserving" can also reduce your fuel consumption."
...and said to myself "No Way!" as excessive oil changing is one of my (many) pet peeves. So I fired this (slightly edited for here) email off to them:
"You only quoted the typical "severe duty" service intervals and frankly, most motorists don't operate in "severe duty" mode. The standard recommended service intervals are far more lenient and I'm sure the auto manufacturers have a vast knowledge base and did extensive testing to arrive at service intervals that are very conservative in order to cover the broad range of operating conditions their equipment is subject to at the hands of the average motorist, yet is not wasteful of resources.
Looking in one owner's manual (for an '89 Dodge car, that just happened to be setting here next to the computer), I see a recommended air filter service schedule of every 52,500 miles, recommended oil changes every 12 months or 7,500 miles, and oil filter changes every OTHER oil change. As you can see that is
more than triple the service life for the air filter,
more than double for the oil, and
FIVE TIMES the service life for the oil filters!!!
As a mechanic I can say even these service intervals can be stretched a bit by a knowledgeable motorist who operates under good conditions and has a vehicle roughly 20 years old or newer (older carbureted vehicles do need more frequent service intervals). I have put 80,000 miles on a FACTORY paper air filter element and have 13 years service on a FACTORY battery and they are still good to go. Not that I would make those intervals a general recommendation to the public; my point is changing filters and fluids at the severe duty schedule is a tremendous and unnecessary waste, not only of the materials but of time and money, especially if it is hired out.
Oil is a finite resource and people are wasteful of it enough as it is. I realize that old habits and old wive's tales die hard but it is high time to try to educate the public to the new realities of auto maintenance. I hope after you double-check this with your own expert(s) of choice, the site gets updated accordingly.
P.S. The statement "when you have a choice, remember that a four-lane highway is more fuel-efficient than a two-lane highway" isn't necessarily so, as traffic on many four-lane highways flows roughly 20 mph faster than that on two-lane roads and you know as well as I the effect of higher speed on fuel economy. It's a "your mileage may vary" sort of thing depending on the route; if you drive 55 mph on a four-lane it can be the more economical choice than 55 mph on a two-lane due to encountering fewer reduced speed zones and stops... but who (besides me) does that?
Also I wanted to congratulate you, for the rest of your tips are good and I wish there was some way to educate more motorists, as it appears to be sorely needed and the only ones we reach on the net are those that are seeking this sort of thing. Every day I see countless examples of excessive idling, jack-rabbit starting and stopping, low tire air pressure, needless autostart use, plugging block heaters in overnight, using full-size V8 trucks as single passenger commuter cars, and on and on. It is quite maddening."
Don't know why, but I decided to pay the site a visit today. I never got a reply to my email but it looks like the site was updated in June, and all the points I brought up have been addressed!
I don't know how many hits they get but if it causes even a few to reconsider changing their oil every 3,000 miles, or not plugging a block heater in too much or too little, or etc., I'll be tickled.
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