Z, I'm certainly not an expert on this and I assure you that I know too well that "oil wars" can be started very quickly on here, so let me try to keep this discussion between synthetic and conventional lubrication, and not particular brands. The Valvoline representative who made the presentation at the TDR-CMEP Tour, who I found out later was an organic chemist and a company trainer for Valvoline representatives, pointed out several things that I was unaware of, or at least had not thought about:
First, according to automotive engineers, 85% of the wear on an engine occurs at startup. It makes sense to have the best lubrication on the wearing surfaces at this time. The synthetic is made up of specifically processed/manufactured long carbon (organic) molecules that are considered ideal for their lubricating properties. They adhere better to the wear surfaces to provide the better protection at this critical time. The lower viscosity of the synthetic also enhances faster and more complete lubrication during cold weather startups, and using the lower viscosity synthetic is possible due to the closer machining specifications of the engine utilizing advanced, state-of-the-art manufacturing processes. Also, using the lower viscosity oil has been proven to improve mileage by roughly 1-1/2% over conventional (dino oil) lubrication.
On the surface, you have a greater justification for using synthetic in Idaho than I have here in Alabama due to the differences in our cold weather temperatures. This would also help to explain the difficulties I encountered when trying to purchase Extreme. However, going one step further, the long carbon molecules that provide the better lubrication when cold during startups, provide better lubrication when the engine is hot. These molecules are less prone to break down at high temperatures and as I understand it provide superior lubrication over the dino oils when really putting the engine to work.
I haven't mentioned the additive package that Valvoline in conjunction with Cummins has developed for their oils. This opens up the possibility for the inevitable "oil war" but as I have said before, I trust the folks at Cummins and I respect the working relationship that has existed for many years between the two companies.
Okay, besides all this, how can you justify the increased expense of synthetic over dino? Of course I could say that I only want to use the best in my truck, and/or you could say to me that you plan to trade yours off before the engine wears out. Hah! Let's go further. If I use dino oil, I normally plan on changing my oil at around 7,500 miles, which is by the book, because I primarily use the truck to pull my 5th-wheel. If I use synthetic, I figure on changing around 10,000 miles, based on better lubrication, superior additives and Blackstone Lab results which I do anyway. I have extended my oil change interval a reasonable, as well as, justifiable 30%. Calculate in the 30% on the oil filter, the rolling around factor on the ground under the truck by a seventy year-old, and I feel comfortable saying that it is almost a trade off, not even considering the increase in mileage of 1-1/2%:
10,000 miles/12 MPG=833 Gals X $4/Gal=$3332 X 1. 5%= $49. 98 Savings Per Oil Change on Fuel
Good luck, and safe driving!
Ed
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