The main reason why I switched to synthetic oil is because the Benz dealer recommended it when I brought my car to diagnose the ticking noise on the valve lifter. After I switched to sysnthetic oil, the ticking noise is gone. No oil leak and the engine runs quiter.

__________________
94 E320 Silver 210000 miles
94 740il Pewter Green 97000 miles- Retired
05 S430 4Matic
07 Lexus IS250

To throw a little fuel on this one, I believe the mandatory teardown interval for aviation engines is so ridiculously short that it wouldn't matter much what you used (synthetic or mineral).

I just switched to 15-50 Mobil 1 full syn on my 92 400E 160K miles. I did notice a differance, better compression, and it seems like my motor runs allot quiter? No leaks so far. Might have nothing to do with synthetic, maybe just the switch in grade of oil, but so far so good.

I resisted synthetics for many years, mainly for their costs.
Based on what I have observed over the last few years, I'd never go back to dino juice.

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2007 C 230 Sport.

FAR's for teardowns aren't that onerous, actually.

my point was that i think avengines are a much tougher lube application than light-duty passenger car engines. just as were the industrial application engines that i cited previously.

and my point persists, if syn is so good, so cost effective, why is it that these more severe service engines are not using it?

as i said before, mobil operated, exxon-mobil operates thousands of stationary, spark-ignited, natural gas fueled, recips. all over the world. yet, virtually none of them are operated on syn. why do you think that might be the case?

it is because there is no pay-back. more to the point, mobil conducts incredible long-term investigations into its lube oils. knowing what i know, if syn was better, mobil would be touting it for their production engines and the engines of others.

but they aren't doing that.

and virtuallly no one is touting syns for avrecips. and they are a more severe service engine that anything that you have ever operated[imho] in your vehicle.

let's go even further, what style lube to you think is being used in the emd and ge diesels that power the railroads? syn? NOT.

let us consider marine diesels, 4-stroke and cathedral 2-strokes. these are real engines that are developing 100% torque throughout their operating life. what kind of basestocks do you think they are using. syn? NOT.

what is so funny here is that the vehicular engine, a slacker among engines[sort of a gwbush in the guard type of engine], gets that miracle lubricant. the only engine in the world that doesn't really need it. but the engines that really work, severe service engines, run on dino.

[QUOTE]Originally posted by albert champion
[B]FAR's for teardowns aren't that onerous, actually.

snip


All I can conclude from your post is that you don't know why dino is used over syn in these situations and you read the NY Times.

glenmore
1991 300CE
1990 LS400

i might read the nyt. but i haven't found it to be truthful for years.

and perhaps you will share with us what that engineering digest, the nyt, has to say about this issue. since you failed to do that earlier. i am all ears.

Albert,

What are the hp/cu.in. values for the engines you mentioned, as well as the operating rpm's?

Thanks.

Don't know about aviation engines (although I can find out easily enough), but I do know what the big thing these days in marine engines is extended service intervals with synthetic oils. They are MUCH cheaper long term, and increase the time between overhauls to boot.

Please note that constant speed/constant load applications aren't what most engineers would consider severe use, unless someone grossly under-sized the engine and it runs at full throttle most or all of the time. I've heard of GM 350 diesels, surely one of the most unreliable diesel engines ever put into production since 1960, running for decades as driving pumps. Low load, always running.

Aircraft engines only see heavy service in takeoff or emergency conditions -- otherwise, they are running well below their maximum output ratings, and there may also be some regulations on oil changes, etc -- no one is going to use expensive oil if you have to change it on short intrevals and disassemble the engine at specified hourly intervals anyway, it's wasted money. That doesn't mean mineral base oils are better, just less expensive.

I get all the noise about cheaper being confused with higher performance I need at work. Price is never the sole consideration for anything -- leave that issue alone, please, and stick with the actual functional qualities of the oil, not the price on the bottle.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Just a wild guess:
Displacement @ 1000 cu. in.
Operating speed @ 1200 rpm.

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2007 C 230 Sport.

Well, I'll tell you why:
1. Being a gaseous fuel, there is no cylinder wash-down from fuel ( unlike gasoline or diesel ).
2. On a gaseous fuelled engine, all the oil is expected to do is lubricate & cool.
Quite often, a non-detergent oil is recommended for these applications.

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2007 C 230 Sport.

well, actually, that is not completely true.

a large number of these engines operate on unprocessed gas, which can contain lots of liquids and other nasty hyrocarbons.

but look, you have to recall, i am not disputing that syn has merits, i am just not sure it offers any real benefits over dino.

and the folks running engines for money have so far voted for dino. knowing what i know about how those entities operate, that is the result both of inertia[i.e., we aren't experiencing any unusual problems with dino - no need to change] and also of cost benefit analysis[i.e., we ran tests comparing syn and dino and after 10,000 hours we found no discernible wear with either - therefore, we aren't going to spend more money for syn].

today, i visited my indy and talked to him about syn v dino. his standard lubricant is dino. he has some full syn on his shelf for his customers that insist on it. my indy does benzes, bimmers, jaguars, ferraris. he says he has no lubrication issues with the cars that he services. that would have been my guess based on the five benzes that i operate.

tomorrow, i am going to take the vp service of a benz dealer to lunch. he has been directing service activities at benz dealerships for almost 30 years. we are going to discuss lubricants.

i shall let you learn what i learn. my guess is that he will confirm my understanding. syn is good. dino is good. both need to be properly selected and properly serviced. for instance, whether syn or dino, i would insist that 3,500 -5,000 mile filter and crankcase change intervals be the norm. changing engine oil in a vehicle is like cleaning toilets. it just must be done at some routine interval. and i think 3,500 - 5,000 miles is the correct change interval, whether the lubricant be syn or dino.

having said that, if it is going to cost me $100 every 3,500 miles for syn as opposed to $35 for dino. dino wins every time. particularly when my vehicle[s] is not experiencing any problems because of lubricant inadequacies.

lastly, the real issue coming up is the one of lubricant availability. if the era of peak oil production has occurred, then there is going to be a decline in access to dino hydrocarbons. many see this problem as a fuels-based one, but most miss the fact that this will become a tribological issue as well. just consider all the lubrication requirements that an industrial society has.

and there is a real question as to whether the historical lubricant suppliers are doing the research to make up a dino shortfall with syn. making the capital investment in syn plant facilities to make up for dino shortfall. a national hydrocarbons policy would address these issues, but at the moment, no one wants to grapple with the oncoming locomotive that will be the decline in dino production globally.

as to those stationary engines that are fueled by natural gas. typical field compressor driver is a 4-stroke, V12 operating at 1,000 -1,200rpm. generally running at 90%-100+% load. engine size, more than 7,000 cubic inches. a well- engineered engine will offer pre-lube and post-lube. turbocharged, though they can be naturally-aspirated. bmeps 120-200psi.

typical daily lube oil consumption for such an engine in good condition, approx 8 gals per day.

in closing, i am not really arguing with you, i am just informing you to a class of engines that probably consume more lubricant per day, globally, than passenger vehicle engines. and that most of them are run as profit-making entities. and on that basis, syn has so far, made no economic sense.

also, imho, there would be no marine diesels running syn. it would make no sense. can you imagine trying to find make up syn around the world? would be impossible. hell, my guess is that vlscc[sic] tankers with the hull built around sulzer, gmt, or b&w cathedral, slow speed 2 strokes[nominal 2,000mm X 2,100mm], at 5,000hp per cylinder[generally i6-i12] that travel from the gulf to houston or bayonne or baton rouge operate only on dino. and these are ships that have a real possibility of running syn. but they don't.

so think about the other marine diesels running from houston, new orleans, panama, guayaquil, vina del mar....well you get my point. you are not going to be finding syn at these ports.

just some thoughts.

but the next oil change might be Amsoil, not that much different in price, and Delvac is really hard to find..

__________________
2000 Ford 7.3 Powerstroke 4x4
2006 Mazda Tribute
1983 Black 300 D (donated to charity)
1993 Teal 300 D (160K) Sold
"I love the smell of burnt diesel fuel in the morning, it smells like ....VICTORY"

Semper Fidelis
USMC 1973-1976

I like your thinking

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'94 W124.036 249/040 leder; 8.25x17 EvoIIs
'93 W124.036 199/040 leder; 8.25x17 EvoIIs, up in flames...LITERALLY!
'93 W124.036 481/040 leder; euro delivery; 8.25x17 EvoIIs
'88 R107.048 441/409 leder; Euro lights
'87 W201.034 199/040 leder; Euro lights; EvoII brakes; 8x16 EvoIs - soon: 500E rear brakes
'70 R113.044 050/526; factory alloys; Euro lights