Synthetic Oil - What kind?

Try www.bobistheoilguy.com for more info on synthetic oil than you can probably process. More than I can take in anyway. It does seem that Mobile 1 is a kind of benchmark that other oils are frequently compared to. I believe Mobile 1 is generally accepted as a high quality product.

I have always subscribed to the theory that changing oil at regular intervals and sticking with the same brand of quality oil, whatever you choose is the best policy. I have used Mobile 1 for several years in other cars and have no regrets.

John

 

> Mobile 1 5w/30 $4.77

Sam's Club sells 6 quarts for $23.33, that's $3.89 each.

 

I've used Mobil 1 since 1994 in all of our vehicles and never had a problem. It pays to shop around for a good price. Sam's Club is the best right now, as John1701a stated, but I guess it's not available everywhere. I managed to pick up 12 qts. at that price, which should keep my Prius, my wife's Corolla and son's Echo good for a while.

 

The simple rule is to pick the right oil: by weight for your anticipated temperature range; and, by classification, which would be specified by Toyota. Having met these requirements, price is not a bad way to select.

I'm open to learn more, but with a maximum recommended change interval of 5,000 miles, it seems that the higher cost of synthetics (offering an extended life) hardly seems warranted. That is, of course, assuming you are comparing synthetic to dino juice with the same weight range and classification.

 

> it seems that the higher cost of synthetics (offering an extended life) hardly seems warranted

First, it is only $10.

Second, the increase in efficiency alone is just about enough to cover that cost.

Third, synthetic protects the engine better. What more reason do you need?

Lastly, keep in mind the fact that our economics are way out of whack. One gallon of milk costs twice as much as one gallon of gas. That's rather absurd. Heck, even a gallon of purified water costs more than a gallon of gas. That doesn't even make any sense.

 

"Second, the increase in efficiency alone is just about enough to cover that cost. "



John,
Are you saying that you get better gas mileage with synthetic oil? I don't have any experience with synthetic oil so I was just wondering.

 

> Are you saying that you get better gas mileage with synthetic oil?

Yup!

I have pretty solid data showing that you should gain 1 to 2 MPG by switching to synthetic.

And on a day like today, where the commute to work was -18F and the commute home was -8F, it's rather hard to deny the 36 MPG average I maintained on those drives wasn't better than you could get with dino oil. Extreme cold is the when synthetic really demonstrates the advantage it offers.

 

http://www.gmp.co.nz/forum/messages/192398-5.html has a few supporters of Super Tech...

 

John,

My point is that using the correct oil, as specified by the manufacturer for the given engine (based on internal passage and bearing clearances, metalurgy, operating RPM range, cooling capability, etc.) will provide you the protection you need. I have used synthetics routinely but not exclusively for many years. In fact, I have no hesitation to use dino juice meeting the manufacturer's specification. The only difference, I will extend the synthetic drain interval compared to a dino juice interval.

You state it is only $10 more. Great for you if it is no difference, but for some $10 here and there can add up. Synthetics cost more because the production is far more complicated and energy intensive. Speaking environmentally, if you aren't extending your drain interval, than you are using more natural resources.

You subsequently state that you have confirmed an increase in MPG. No offense, but that doesn't hold much water or oil, given your testing criteria is so easily influenced by other factors (e.g., wind direction and velocity, ambient temperature and humidity, hills, altitude, etc.). If this was indeed true (as in verifiable), wouldn't each synthetic manufacturer be shouting it from the rooftops?

Synthetics must match the same criteria of whatever you pour in your crankcase. For the most part they do, but as an example, certain Mobil One's (as well as other synthetics) do not meet the manufacturer specification for my wife's 1998 Mercedes. Of course by spec I am not referring only to the weight range, but the API classification rating of the oil, and Toyota's own specification (number?), if they bother.

And, I fully agree with your milk statement. What often bothers me (take now, for instance) is when the public is misled into spending more than is required, and hand in hand, causing more environmental harm than necessary. Case in point, remember all those ads pushing us to use high grade octane (Put a Tiger in Your Tank!; Drive your Engine Clean!) in everyday cars. Well, the vast majority of those cars didn't "notice" the difference, and the same fuel cleaning additives were present across the octane range of most gasoline brands. Besides the extra cost, the production of higher octance gasoline uses approximately ten percent more crude oil. :cussing:

 

Howdy SpartanPrius,

Are you arguing with John1701a The Prius Master? You are a daring fellow.

If you would like to continue the disscusion on fuel octane you should check out my post under "Oil Change" in the "Prius Main Forum."

Sincerely,

~Andrew

 

True. Yet, I find it hard to get those Frosted Flakes down when they're swimming in regular unleaded.

BTW, would 87 octane be the functional equivalent of skim? :lol:

 

I am merely a humble servant posing a polite discussion. I do not now, or in the future, seek the throne.

Only so far as its degreasing properties allow. :wink:

 

Regarding blowby, bear in mind that synthetic is able to absorb impurities better than dino oil, so you will still be able to safely extend the change interval using synthetic oil.

Case in point, my 1991 Plymouth Laser Turbo with 137K miles has been using Mobil 1 ever since its first oil change, and I've always changed it (along with a new filter) every 10K miles. The engine never had any work on it, other than a routine timing belt change at 60K. It always started immediately, never smoked, didn't burn oil, ran great.

 

It would be interesting to get an crankcase oil evaluation done on both cars. I've never done this, but would imagine it is not too expensive. I'm not sure that the test would differentiate the gasoline hydrocarbons, but as you said, it certainly would confirm the blowby description provided by ericrernst.

Overall, I would not feel comfortable extending my change interval beyond the manufacturer's recommendation (synthetic or dino juice). Perhaps I'm conservative by nature, but even while using synthetic oil I've never done this. My concern is that there are a number of factors detrimental to engine oil specific to the engine application These include, but are not limited to: physical shearing of hydrocarbon molecules; blowby deposition; operating temperature throughout the engine's environment; and, narrow lubrication pathways that may be prone to fine particulate build-up (e.g., hydraulic lash adjusters). If we knew these factors for the Prius and how they would be influenced by a longer change interval using synthetics, then and only then would I consider it.

 

I just paid $23.70 at Costco for 6 quarts of 5-30W Mobil 1. Since I just changed my oil at around 1100 miles I'm going to wait until 5000 to go to the Mobil 1. My avg mpg right now is about 46.3 mpg and I'm going to try to establish some sort of stable avg before I switch. But by the time I do switch, it will be warmer and we'll be back to summer gas so even a 2-3 % gain will be tough to determine. I'm also going to stick with the Toyota recommended 5000 mile change assuming that I'm way safe doing that with the synthetic.

So assuming a 5000 mile VS 3500 mile oil change I would probably do with regular motor oil, gas in San Diego at $1.799/gal, $3.95/qt Mobil 1 VS $3.27/qt that Toyota charged me on my oil change, $10.63/filter, $3.99/ gasket and lastly at 1% mpg improvement...the cost is $0.045/mile Mobil 1 VS $0.064/mile regular Dino Oil, or about $95/5000 miles. Yes this is contrived because I could probably go 5,000 miles with the Dino but I do feel safer with the Mobil 1 stretching it to the Toyota recommendation. Sooooo, remind me again why I'm doing this calculation, lol. Anyway it appears to be a wash but I want to do everything I can to crack that magic 50 mpg barrier this summer so what the heck, it can't hurt and might even help a little.

 

I've been using Mobil 1 synthetics for my last 3 cars. I have gone double the oil change interval recommended, once out of the warranty. Each car got an increase of over 2 MPG. (I also switched to synthetics for the transmission and differential at the same time.) The increase was pretty easy to see, since the diesel mileage doesn't fluctuate as much as I hear the Prius does: 42 overall with my city highway mix, and 44 on some trips at 55 mph.

As I wait for a Prius my old 190D is approaching 250,000 miles, and the engine is the only part of the car that has been trouble free (other than exhaust systems rotting out).

With a diesel, in New England, synthetics are pretty much required, for cold starting. The same thing that helps starting (faster cranking at cold temperatures) should help with cold weather mileage too. The car starts reliably to 10 below 0, with the new winter viscosity oils. At 20 below the block heater would be needed.

Warning: Regarding the oil change interval, this is dependent on driving conditions, crankcase capacity etc. I picked my 10,000 mile change interval (still with 5k filter change) after extensive oil analysis testing, back when I first started using synthetics. So I am not suggesting anyone extend oil change intervals in a Prius, especially with it's much smaller crankcase.