That's a good feature article on synthetic oil. This has been an age old argument: Coke and Pepsi, Chevy and Ford, Synthetic or Non-Synthetic.
The plan was to use the Synth to make a lower-friction environment and thus better FE -- not necessarily a longer change interval. I understand now if you use the same weight formulation (e.g. 5W30), you're probably getting the same lubricity as that of Dino-oil (granted it might have some more robust properties about it in other categories such as oxidation). I follow the car's oil life indicator regardless, which when driving in GasSavers mode, yielded nearly 6000 miles on good old oil, at an average of around 30-some mpg from mile 000007+ (what's cool about the car is that it "remembers" 2 Avg. FE numbers: Avg "A" is automatically reset at each fillup and calculates that tank. Avg "B" looks to be a running tally since the beginning).
So, to save a lot of $$$, I've decided to go back to regular oil next time -- no real advantage. Trial and Error I 'spose.
Now -- how about the advantages of synthetic Automatic Transmission Fluid? The Integra may be due soon.
Changing oil every 3,000 is an unecessary waste for most.
So is eating; so is sleeping (in excess)....
Ah, yes! So is the draining of the acids! have you ever smelled the drained oil? Compared to new oil? Acids + soft metals in your engine (cam bearings, rod 7 main bearings, bushings, etc.) aren't exactly compatible! Especially hot!
Admittedly, oils are indestructable...but how much acid is too much? Where else are the blow-by acids (the source) to go? Unlimited oil life (like in a tranny or a final drive unit) is a function of power (pressure) derived fron a ring-sealed piston engine.
"When I see an engine run for 300 hours at full
throttle/max load on an engine dyno with conventional oil and then at
teardown the bearings are not even touched and other wear surfaces are
fine it is hard to understand just how much "better" synthetic oil could
have run....LOL. I have seen LOTS and LOTS of engines run like this
and somehow, miraclously, the engines always look fine with conventional
oil. And we don't even add Lucas or Slick50 or ZMax or ? LOL If
you are using synthetic oil, what gain or advantage do you expect?
I understand the idea of putting the "best" into something and if you
want to use synthetic I have absolutely no problem with it....just don't
expect miracles and realize that the likelyhood of really exploiting
the advantages of the synthetic product in a street engine is pretty
Furthermore, in conventional engines there is very little metal-to-metal contact. The bearing surfaces have enough area to prevent any metal contact, so there is no friction. I define friction as the resistance to two solid objects in contact with each other and sliding against each other. In a new engine there should not be any metal-to-metal contact, hence no friction.
There is something else going on called 'viscous drag'. In short, this is where two moving parts are separated by an oil film, which is how plain bearings work. From what I remember, viscous drag is determined by the distance between the two parts, total surface area, and the viscosity of the oil film. So changing from dino oil to synthetic at the same viscosity won't change viscous drag, so FE should remain the same.
I will keep running my M1. I get 10k mile plus oil changes.
When I put M1 in my then new 1992 Olds Delta 88 after break in. Same wieght 5w-30. The wife and I laughed at the car when I started it up and it had to readjust it computer. Cant prove it was from less friction. But some thing had to change when the oil did.
09 HCHII, w/Navi
07 Mazda3 S Touring, 5MT
Mild Hypermiler or Mad Man?
So, I'd like to know how, (in the "olden days"), the powers-that-be proclaimed:
Thou shalt not go beyond 3000 miles in thee's oil change interval.
Was there some sort of testing, or did oil just "look dark enough" at that point. I think it was when garages would pump your gas, check the oil, etc., that the notion was driven home: sell more oil changes, filters, and oil.
I grew up with my parents having that mentality -- older cars maybe needed it. But now, with processors that calculate the oil life based on numerous variables in engines with stricter tolerances and better build quality:
In many cases, it would be more expensive to change the oil at 3000 miles for the life of the car than to replace the entire engine
I fully expect newer cars to run on whatever lubricant, dino or synth, for 5000-7500 miles without friction-related failure for 150K miles+. I know someone who didn't change the oil in her '98 Camry for 25,000 miles (or what oil was left -- she just added some now and then). The car is still running today! Granted the dealer flushed it when it wasn't "running right", but she reported a huge increase in fuel economy It probably has over 150K on it now.
That's an extreme/outlier. Let's say you drive 15,000 miles a year, and the average oil change/filter over 10 years is $30.
At 3000 miles, that's 5 changes a year X $30 per change X 10 years = $1500 for 150,000 miles.
At 7500 miles, that's 2 changes a year X $30 per change X 10 years = $600 for 150,000 miles.
I can think of a few things other than oil to spend $1100 on.
If the oil change is more expensive, then the benefits are even better -- crunch some numbers to find out. You might be able to have enough for a brand-new engine at 200,000 miles!
Nice numbers rh77. You know this forum has high standards when members use technical terms such as 'outlier' in casual conversation.
I found a compromise that works for me. I change my oil every 4000 miles with synthetic (since I have a modified turbocharged engine). I change the oil myself so the cost to me is $25 per change. That's $975 for 150k. I changed the main and rod bearings last winter for the first time in 195,000 miles since the clearances had worn beyond factory specs. A set of bearings cost about $75. I guess I'm good for another 100K.