Please post any real world numbers you have on differences you've noticed (or not) in MPG between synthetic and dino. I'm only interested in long periods of records in order to account for weather, driving conditions etc. Thanks.
I don't have list of documented events but I do have some real life experience... I first learned of synthetic oil decades ago when a mechanic where I worked put paper cups of synthetic and natural oil outside the shop door one cold winter night. The next morning he poured the oil out of each cup. The synthetic poured just fine but the dino oil was like cold molasses. The conclusion drawn was that synthetic is better in cold weather conditions, especially for cold starts. I have drag raced for years. After taking into account temperature, humidity, altitude, traction, shift points, and a great many other variables I have concluded that in my Camaro, synthetic oil is good for roughly about 5 horsepower over conventional oil. That may not seem like much, but the end result is by freeing up horsepower the engine works more efficiently. Translated to normal street driving there should be some sort of fuel economy gain all other factors being equal because the engine does not have to work as hard to produce power. Synthetic oil generally does not have to be changed as frequently so over the lifetime of a vehicle you will probably use half to 2/3 less total oil in the engine in normal use. Synthetic oil tends to hold up better in high heat conditions and is, in general, more "slippery" than conventional oil. The bottom line for me, living in Maine, is that I use synthetic in our vehicles. I stay with the same brand of synthetic (in my case Valvoline), and have had no negative experiences that I can attribute to using synthetic over conventional oil. If an engine has a bad seal or gasket, synthetic will likely leak more quickly than conventional oil, but that is not the fault of the oil itself. Older cars that were not designed to be used with synthetic oil may have issues. Modern cars in good condition should handle switching to synthetic just fine. As a footnote, I recommend avoiding additives, but that is another discussion.
I have used Mobil 1, Redline and now Amsoil. I believe Amsoil can't be beat as far as quality and their filters are second to none. My last vehicle was an 04 Fronteir which before getting totalled had logged 475,000 miles and on a compression check I still had full compression with only 5psi between the lowest and the highest. I was only consuming 1qt every 9K and changing every 17-19K. The benefits of a quality synthetic oil and a good filter are not up for debate. Less wear,Longer change intervals and increased mpg. As far as the green concept changing less often=Less waste for you tree hugers out there
While I don't have any "numbers" to back it up, I had an '07 Camry Hybrid bought new in '06. Apparently, it came with synthetic oil and the MPG was close to what the sticker said. The first two oil changes were "free" at the dealer and for the first one they put in dino oil, which made the MPG immediately drop by a significant amount. I questioned them about it the next time and they said they don't put in synthetic oil because it didn't matter and it was all a myth. Anyway, for the third oil change, I bought Amsoil and there was an immediate and significant increase in MPG. Now, as for the brand of synthetic oil, I would prefer Amsoil with Toyota oil being second and Mobil1 third. Although, there is only a slight difference between the three. In other words, they are all great and you won't go wrong with any of them. One thing that I don't buy into is that the price of dino oil affects synthetic oil. You would think that synthetic would be a bit cheaper, but it aint. As for "eco-friendly", I would never dump any type of oil on the ground regardless of what kind it is. I have seen people park their cars over a storm drain and let it out. If I could have turned them in to "whoever", I would have done it. With all the recycling, it would seem that oil changes at a reputable place would be about as eco-friendly as a normal person can get. Even it you change your own oil, there are places you can dispose of it properly. Speaking of that, I grew up on a farm. My grandfather saved all the used oil and would reuse it for lubrication of all the moving parts on the equipment. Rarely did any of this oil hit the ground. We were into recycling before we knew what recycling was....
Quite a bit of synthetic oil is made from petroleum base stocks. It requires more refining than conventional oil so costs more to make. I don't know the cost of other synthetic oil base stocks, but the lack of a low priced group IV or group V oil from anyone suggests it costs more to make a Group IV or Group V than regular dino oil. Edit: Found this: This source ExxonMobil's Ultra High Viscosity Index Poly Alpha Olefin Lubricant Blend Stock :: Phase_2010 :: Process Economics Program :: SRI Consulting suggests that PAO costs $2500/MT to produce. That's about $2.30/qt for the main ingredient for high end synthetic oil with no allowance for profits, packaging, advertising, shipping, taxes and all the other expenses of doing business. $8.00/qt for a PAO based synthetic in the store sounds reasonable to me.
I always understood synthetic oil to be created through processes that do not occur naturally. In other words, synthetic applies to the process of product creation, not the base ingredients. My understanding is that "all natural" as applied to food has about the same level of understanding by many consumers. I also have read that "fresh" turkeys are required by the FDA to be chilled to 26 degrees F... Last time I checked that is below freezing.
I highly suggest anyone interested in synthetic oil look to Amsoil first. Feel free to PM me with any questions you might have.
You have a point about Group III oils being iffy "synthetics", in many countries they aren't allowed to be called synthetics. However, their performance is still superior to conventional oils. By your definition, true synthetic oils, such as PAO oils, which are commonly made from petroleum base stocks, should be disqualified too. Why do you care where the chemicals that make up the oil came from?
Well, if I am going to spend a lot of money on a car, I would not want to put just anything in the engine. What good is a car if it won't "go"? If they claim it is full synthetic, then there should not be any dino oil in it that could cause trouble. I remember McDonalds used to claim their Big Macs were made with "all beef" patties. I have not heard that claim in years. Could it be because of all the other junk in the patties that is not exactly beef but you can't really tell what it is just looking at it? I have stopped eating there altogether, btw....
Your car's engine will outlast the rest of the car using modern good quality dino oil with reasonable oil change intervals.
I first started using synthetic oils for proven performance at cold temps, especially -40 I never did care about fuel economy, just proven cold temp reliability In a moderate climate, using reasonable oil change intervals, the motor will probably outlast the rest of the vehicle At -30 F and colder, use a dino oil and you will start to have problems
