Re: Automakers Lengthen Oil Change Intervals

On Fri, 30 Mar 2007 09:49:46 -0500, (Brent P) wrote:

Too bad YOU cant read. What part of "I don't recommend them" do you not understand??????

Actually, I HAVE had the data to back it up. When I was Toyota service manager Toyota was recommending 5W30 oil year round. They were replacing the odd camshaft. They were replacing timing chains. They were having problems with timing chain tensioners and guides. I was in conversation MANY times with the engineers, and they said they "could not recommend 10W40 and 20W50 oils for use in their vehicles because it would contravene the laws in place regarding C.A.F.E." I was free to recommend whatever I wanted to recommend to my customers as long as I did not intimate that Toyota suggested it. They said there was no engineering reason why 10W40 and 20W50 oils could not be used if they were changed often enough to avoid viscosity breakdown. And guess what? NONE of my customers EVER had a camshaft or timing chain or tensioner problem that required the engine be dissassembled or repaired. NOT ONE. I did replace a fair number of camshafts, timing chains, and tensioners in vehicles that had been serviced by other dealers, following the factory recommendations. Any question as to why my retention rate was the highest in eastern Canada? On a 3 year weighted basis, I was servicing more cars than the dealership had sold. That's seeing the car more than twice a year for service when the car was 3 years old or older.(long off warranty)

Accelerated life testing was done by several customers who used tercels for delivery service, racking up opver 500,000 in 2 years. And by others running Hilux pickups for courier service, with about the same mileage accumulation. And customers who commuted 160 miles a day with Supras, and kept them for 5 years. And for your information, I never did a BOGUS transmission flush. Did I do transmission flushes? Yes I did - and I NEVER had an automatic transmission failure on any of my customer's vehicles. NOT ONE. (and no specialized megabuck equipment to do the flush either) The transmission flushes I did were not "cash cows" - straight time and material. (I was in charge of what was likely the ONLY non-flat rate dealership repair shop in eastern Canada at the time.) I changed the transmission fluid at the manufacturer's specified intervals, and flushed to replace ALL of the fluid, not just part of it. I had over 600 vehicles under my "exclusive" care, as well as several hundred more that came to me for some of their service, and went elsewhere, or did it themselves, for the rest.

That says a lot.

And what products? I've done product development too.

No, as I said YOU should follow the manufacturer's recommendations to the letter. YOU trust the manufacturer to always do what is best for you.
I'll go by my experience, and my training and knowledge. Those who know me and trust me will take my advice. They have for decades. I'm not expecting you to.

Well, I know most manufacturers did NOT test with 10W40 and have failures that were prevented by using 5W20.
The ONLY reason 5W20 oil saw wide adaptation in the North American automotive market was for fuel economy reasons. The critical clearances in today's engines are virtually the same as they were 35 years ago. Precision and finish are perhaps better today than then,allowing nominal clearances to be SLIGHTLY closer than they were because MINIMUM clearances have remained the same. (less "peaks and valleys")

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