I won't pay the extra for synthetic if cheaper dino works just fine. There's a few reasons. One, the vehicle that I drive daily (2004 Ford Mustang V6/Auto) has 326,000 miles on it. I have all the service records from day one-and it's a STACK of paper, all just regular maintenance and upkeep-occasionally a repair (rack & pinion at 190,000, ball joints at 224,000, etc). Normal wear stuff. I was thinking about oil the other night and spend 2 days looking through the records. Never once did it ever use anything but el cheapo motorcraft 5w30 and a motorcraft oil filter (FL400S).
In my truck (03 F250 4x4 7.3 diesel), I have "heard internet hearsay" that they "like" T6 5w40 in the winter months. I do know that I can tell when it's time for an oil change. These engines use HUEI injection (google it)--so they're sensitive to oil quality. When the oil's getting time to be changed I can tell. Rougher idle, little more noise, sometimes a haze of exhaust black smoke when I'm pulling hard. So a couple years ago I spent the $100 for a bucket of oil. Remember, these things hold 4 gallons, so I bought 5 gal bucket thinking I'd have a gallon leftover for the next oil change. I even sucked the high pressure oil pump's reservoir dry, and refilled it with clean T6.
I noticed zero change in MPG. It was not "less cold natured". It didn't run any better than comparable dino. An oil scan was done, and showed nothing to warrant it's additional cost. I went back to Kubota 15w40 and that's what I still use to this day. Thus, my opinion is that it's a waste of money in this application.
Let's go a little deeper. I work for a dealer. 2 years ago I was asked to go to an in-depth technical school for work, had to deal with lubricants ONLY, and nothing else. This was really in depth all the way from the basic elements that make up the fluids to the final product and how it relates to specific applications. Many don't know it but there's 5 grades of synthetic engine oil base stock-which is the base chemical on which the lubricant is made of. Grade 1 is the lowest, cheapest kind. Grade 5 is the most expensive and from a lubrication only standpoint, the best. Grade 1 and 2 base stocks are what 99% of "synthetic" engine oils are made of. Why? Cheap, easy, it can be called "synthetic" (even though it's more dino than syn), and gives satisfactory results to MOST consumers. Grade 5, for example, is not available to most of us. Why? Because it's expensive. And....what most people don't know...is that synthetic oils DO NOT PROTECT as well as dinos do...the higher the grade, the less protection over time. In other words, it wears out. Stuff rusts. You guys call BS and that's fine, you have your opinions on what I've learned. If I learned incorrectly, I want to know about it but this was a trusted lubricant manufacturer's 5 day seminar. What was most interesting to me was that only a few oil manufacturers have grade 4 and 5 base stock-and it's to be labeled race only. Why? Because it doesn't last. During my 2 week stay over there, I seen dyno results before and after on a popular 1,000cc crotch rocket. Made 181 hp on the dyno with 10w40 dino oil. It was flushed then switched to their highest grade synthetic and made 204hp with not a single other change. But when the oil came out after running an hour at 14,000 RPM, it was trashed. It felt weird on my fingers, almost like diesel fuel. It does not have the long term strength to maintain viscosity over any appreciable timeframe, hence why it's rated for race use only because it gets changed often. It's $30.00 a quart or thereabouts. I'm going to try some in my drag car and see if there's any ET or MPH change. Just for giggles. But it's hard to justify spending that much on just oil not knowing what it'll do. Currently running Kubota 15w40 in that, too.
Just my experiences, and some of my opinion, for what it's worth. And I'm out of this discussion from here on out....these threads usually end up with "I use it so it must be better", or "here's proof"...from a 3rd party website...
