bacardi11

iTrader: (1)

funny thing about synthetic oil, Amsolil was the first to come out with synthetic oil before Mobil 1.

SC43052

+1
I'm a Mobil 1 user since late 70s.

I run the Mobil 1 0W-40 Euro blend in both the SC and my BMW ($25 for 5qt jug at Walmart).
I don't really need the 0W low temp starting capability, but I do like the high-temp high-shear protection of the 40 grade here in Scottsdale AZ when it hits 115F and I push it hard on the mountain road, or sit in stop and go traffic down in the valley where the asphalt can hit nearly 200F.

Drain and fill with filter every 5K miles (yeah I know it is overkill, but oil is cheap compared to an engine).

SC43052

Amsoil was early to the market with an API certified synthetic oil sold to the general public for use in passenger cars.

Synthetic oil was first synthesized in the late 1800s. Standard oil did some limited production in 1920s, but determined that there was no demand given the cost. Both Germany and the US Defense Department utilized synthetic motor oil in WWII (the Germans partly because their sources for crude stock was cut off, and both Germany and the US for its superior viscosity index). The US Army used synthetic extensively in aircraft engines and vehicle engines, especially in Alaska. The CEO of Amsoil was a former US jet fighter pilot who personally witnessed the advantages of synthetic oil used in aircraft in the 1960s.

Gulf oil created the first commercially viable method of producing base stock in 1951, and synthetic was available for special industrial lubrication applications until the 1970s when Amsoil felt the time was right to market the superior low temperature starting characteristics and resistance to shear down which produced the low part wear characteristics of synthetic.

Amsoil is referred to in the industry as a "boutique blender". They do not make base stock, meaning the do not actually produce synthetic oil. They purchase base stock from a number of base stock manufacturers (such as Mobil/Exxon) who have the industrial infrastructure to produce Group IV PAG synthetics. Amsoil then blends the base stock with additives purchased from other companies in a special "recipe". Amsoil produces very good finished motor oils.

Today, Group III oils (heavily processed dino oil) is coming very close in performance to true synthetics, but given the relatively cheap cost of purchasing synthetics in 5 quart jugs from discount retailers, IMHO the price difference is not worth using anything but Group IV based motor oils if you intend to keep a vehicle for a long time.

bacardi11

iTrader: (1)

sc430
that's a great right up about synthetic oil. I know Amsoil was the first then Mobil 1 started selling it for cars.

FLYCT

I am not aware of any fully synthetic oil approved for piston aircraft engines. Sure, for kerosene burning jet engines the synthetic oils perform well.

Back in the 90's, Exxon/Mobil came out with a fully synthetic aviation oil, AV-1, which caused them millions of dollars having them replace every aircraft engine that used it. 100LL Avfuel contains lead and AV-1 couldn't handle it. They pulled it off the market back around 1995.
http://www.avweb.com/news/news/182891-1.html

AV1 100% synthetic Aviation oil failed to keep the lead in suspension which gummed up engines. Stuck rings, low compression, internal engine corrosion, clogged prop governors etc.

Car engines burning lead free gas is a different story.

I was an early user of Mobil One in a 300zx back in the 80's. After using Mobil One that car began leaking oil from multiple seams and gaskets. It was consuming 1/qt per 1,000 miles. Today's engines are designed to be able to handle synthetics but I still like old school proven Dino oil for my SC430.

jzwu

For street cars, dino oil is good enough. Synthetic oil is really overkill. I use Mobil 1 5w30 for extended oil change at 10k miles.

SC43052

There are semi-synthetic oils Aero Shell 15W50 for gas piston and full synthetic Aero Shell Diesel Ultra for diesel piston (J-1899), but you are correct that after the industry discovered the insolubility of lead in synthetic oils it pulled back from the market rather than chase the market, even though failures were not universal and the FAA was willing to work with oil companies on the problem.

I raised aircraft use of synthetic only as a point of history, but if you are an A&P, you know that aviation piston engines are a totally different animal than auto engines, with the average aviation drain interval of as little as 25 hours operation (50 hours for full-flow filtration) and regular scheduled short interval examination of engine internal components as well as oil pickup screens and filters for insolubles.

And if you are an A&P you also probably know that upwards of 80% of the GA aircraft actually can operate on premium unleaded mogas and don’t really need 100LL. Given the current push by the FAA/EPA to develop non-leaded alternative fuels I don’t think it that long (years but not decades) before synthetic oils could reenter the aviation piston power plant market. Just last month the FAA accepted four unleaded avgas formulations for Phase 1 testing to replace 100LL. Whether oil companies will reenter the market is hard to say, as the cost/benefit ratio of synthetic may never truly fit the GA market, given short drain intervals in existence.

I don’t know how many miles you had on that engine, but not only have machining tolerances and gasket materials changed, but all oil manufacturers, both dino and synthetic have made huge strides in additive technology, including gasket swell characteristics. Luckily for you the “old school dino oil” you speak of is long gone, with today’s heavily hydroprocessed mineral oil base stocks and exotic additives making quality name-brand dino oils almost as good as synthetics. And if you are changing dino oil every 3K miles I couldn’t disagree with your choice except in the most severe conditions (such as ambient temperatures of -30F starting or 115F high shear conditions), where dino oil pour point and anti-shear additives can give up early.

FLYCT

SC43052,

Very impressive, accurate replies.

Yes, aviation engines are very different animals. My last plane had a 540 cubic inch 6 cylinder high compression engine, red lining at 2400 rpm. It had an 84" prop directly connected to the crank shaft.

25 hour oil and filter changes, remove/inspect oil screen, cut open and inspect full flow oil filter for metal and oil sample sent to Blackstone for oil analysis each oil change. When your life depends on reliable engine, things are looked at differently.

My 300zx had 50,000 miles on it when I switched to Mobil One.

SC43052

Whoa, you were flyin' a big dog!

182? ... Bearhawk?

FLYCT

R182 Skylane RG II

sorka

I used to use Mobile one in everything until the late 90's when I realized it was just overkill and really made no difference. Plus if a car has an even slight tendency to burn oil, using synthetic will make it way way worse.

Since the late 90's I've used the cheapest oil i can possibly buy which has always been Walmart Supertec.

I used Supertec 10w30 in my SC400 for 334K miles at 10K change intervals. A fiber-optic bore-scope inspection at 300K showed the original honing cross hatches on all 8 cylinder walls. Compression at 300K measured 174 to 175 on all 8 cylinders which the spec for factory new. It's remarkable to have such even compression all the way around at such high mileage.

I've used the same oil in all my other cars including my Prius which is about to hit 200K and has only ever used Supertec.

Supertec is made by Warren and is exactly the same oil you get at any dealer as standard shop oil unless you're paying for something more than standard shop oil.

tennman117

What brand filter do you use and how often do you change it/

sorka

I always use the genuine Toyota filter. For the SC430, I use the 90915-YZZD3 which is the slightly longer truck version. I buy them by the case (10 in a case) for $45 free shipping with no sales tax.

$4.50 for the factory filter is not much more than the cheapest Fram. I've cut both in half and there's a world of difference. Stick with the factory filter for sure.

tennman117

Do they go 10k between changes?

Also, where do you buy them?

sorka

That all depends on the type of driving you do. On my SC400, it was almost all long distance freeway driving so the oil looked almost new when draining at 10K.

Our SC430 is driven much more stop and go and I've been changing it every 5K.

I change the filter when I change the oil.

I also do a drain and fill on the trans every time I change the engine oil.