synthetic oil revisited

[67hat34c]

we discussed the value of synthetic motor oils in the past but I though i would bring it up again.

I have a 15year old honda walk behind lawn mower that finaly had to go, engine ran perfect but the rest of it was not worth to fix. so I dismantled the engine so i could see what it looked like after that many years, guessing 500+hours on the motor, Florida lawn. I have used mostly synthetic oil in it and change it when ever i think about it. any how i was very surprised what i saw when i took it apart. I could find basically no wear in the engine anywhere, the aluminum castings were perfectly shiny aluminum, no brown tan. crank , cam and over head valves were perfect , piston was perfect. all bearings and sleeves were perfect, rings and cyl walls perfect. Motor is only 4.5hp so not worth to save . anyhow i am saving the major parts to show off. True testimony of Honda small engine quality and I belive the Synthetic oil value. Did not use any particular brand, valvoline, MobileOne, and mabe some Amsoil.

 

[SKYCHENEY]

This is probably due to the fact that you used synthetic oil and to the fact that it is a Honda. I have a Honda rear engine rider that we purchased new in 1983. It has a 38" deck and has mowed 2 1/2 acres of Michigan lawn every season since new. I, too, have always used Mobil One and changed it every spring. It is still running as good as new and I think the deck will probably wear out long before the engine and transmission. It is really an amazing piece of machinery.

 

[Norm Mayer]

Another view is maintenance. I have had many engines over the years, and any and all of them have outlasted the vehicle it was in. I have NEVER worn out an engine. I use regular (usually Valvoline) oil, and even after 300K miles on a Toyota, there were still hone marks in the cylinders. I think synthetic oils are good, just not worth the price difference in an engine. Put synthetic in a transmission, outdrive, transaxle, etc and then it easily pays for itself.
IMHO

 

[Capt K]

Put synthetic in a transmission, outdrive, transaxle, etc and then it easily pays for itself.
IMHO

I agree with Norm. Even in both of my Harleys, I run regular oil in the crankcase and Redline synthetic in the trans, primary, etc.

With the bikes, the synthetic questions of compatability with the seals seems to come up every few years, so I like regular oil with regular changes in the engine.

K

 

[MikeP]

Synthetic oil is better. BUT, is it worth bothering with?

In my drag racing days, replacing regular oil with Mobil 1 was worth 5 HP in a 600+ HP engine. Doesn't sound like much but if you have 5 more HP than the next guy and all else is equal, you win. I ran synthetic in every car I have owned and or raced since Mobil 1 came out.

The superior quality of syns is well known both for longer life before the additives are exhausted and reduced friction and, therefore, reduced wear. But willit help at all with DDs? The answer in my mind has to be absolutely not. Any advantage of syn is more than offset by the looseness of these engines and the amount of oil they use.

I use it in the NL genny though. But I don't use it in Mcycles with the clutches integral with the engine oil system (most of them nowadays) - too slippery.

 

[Maynard Rupp]

We have learned the hard way with airplane engines. Synthetic oil works great, (and is required), in turbine engines, gearboxes, and other rotating devices. It is the worst thing you can use in a reciprocating engine. Synthetic oil has no film strength and it allows pistons and cylinders to scrape, gaul, and jam the crap that scrapes off into the ring lands and crancase oil. It has no benefit for recip. engines, except maybe Honda mowers.

 

[SKYCHENEY]

The only way synthetic makes sense from a cost standpoint is if you can reasonably extend change intervals. They claim that you can. I will admit that is what appeals to me. I like to only have to change the oil in the mower once per year and in my car every 10,000 instead of every 3000 miles. Is this any better or worse than dino oil at shorter intervals? I don't know, but it saves me time and doesn't really cost any more, so that is why I do it.

But in the boat: Exxon XD3 40wt.

 

[MikeP]

It has no benefit for recip. engines, except maybe Honda mowers.




If I understood your statement correctly, I completely disagree - It contradicts everything known about the difference between syn and regular oil. The fact that cars like the Porsche 911 come factory-filled with Mobil 1 with a recommended oil change interval of 15000 miles - pretty much tells it all. They are not interested in having engines break which have to be repaired under warranty so they would have NO interest in using an oil that causes piston ring/cyl wall galling, etc.

All the automotive data show the superiority of syn oil. Whether it's enough to be cost effective is a different issue.

 

[Traveler 45C]

All the automotive data show the superiority of syn oil. Whether it's enough to be cost effective is a different issue.

Got to ask, why use it then?

Would it be wise to start using synth oil in an old eng (Chevy 350, 180k miles)? Burns maybe a quart every 3k.

 

[thoward]

I use it in the race car but we are turning a 1200cc aircooled VW engine 7000rpm . It protects the bearings and I suspect that is why Porsche uses it. Heat is the other factor, petro oil will not stand up to 350* oil temps. Turbos and such are really hard on oil too. For a standard daily driver I see no reason for synthetic but it is a must in hot rod engines.....

 

[Boss Lady]

Do not use it in a Detroit. Most modern engines have been engineered to use synthetics. I am not an oil expert, however, Detroit has had many science experiments go bad when trying to use other oils. All my cars have synthetic in them and my V-twin motorcycle. The systhetic oil is specified by the manufacturer.

Here is an interesting link about Rotella multi-grade oil going 1,000,000 miles without an oil change in a big truck. http://www.gulfcoastfilters.com/1,000,000 MILES.htm
This is regular oil, not synthetic by the way.

So I am still not convinced that we need anything more than regular 40 wt for our old DDs. We know that 40 wt gets the job done.

Look at this article on filters also.
http://www.gulfcoastfilters.com/why_do_we_change_oil.htm

 

[luckydave215]

In exterme lubrication scenarios synthetic oils are markedly better.
Back in my pro racing days syntheric oils were just hitting the market and I picked up a sponsorship with one of the manufacturers.
We (the team) recorded notably less spalling of cam followers (the cam buckets on air cooled double overhead cam AMA superbike engines, as extreme a test as you can find)
Before we used syntheitc oils, we had to replace all the buckets every race, after we got the "magic oil" they lasted three races. The failure mode is spalling of the hard chrome rubbing surface.
Keep in mind, these engines had "rock'em sock'em" cams to make the kind of race winning power we needed, and of course the engines spent long periods at full throttle and full rpm (12,000+ rpm and roughly 150 horsepower out of 750cc on gasoline).
Our old fashioned very low performance Detroits likely won't benefit much from the improved lubrication of these oils, but they would benefit from the improved high temperature tolerance synthetics feature when we take into account the hot running turbo parts.
HOWEVER, no one to my knowledge makes a 40wt synthetic, and our engines were designed before multigrade oils were developed (real dinosaurs) so the clearances are huge to allow cold 40wt to flow through the bearings and piston ring lands.
I, like Todd, use full synthetic oil in my current race car, which is a 2.5 litre turbocharged 951 Porsche making 370 horsepower. Synthetic oil makes a measureable difference in this engine, we could never get away with this kind of output density without it.
Relaxing on the couch in front of a big screen near the central heating outlet holding a beer from the fridge IS better than crouching over a smoky fire shivering in a cave..............synthetic lubricants ARE better than petroleum oils.
Those who say otherwise don't like progress, they feel it's passing them by.

 

[spartonboat1]

Response on syn use and severals posts: aircraft, extended use in cars, marine, where most valuable in recip engines, and trannies.
1) Aircraft- I was lead to believe that recip aircraft generate precipitates that are unique to recip engines and which cannot be tolerated by synthetics. In that sense, use of synthetics in aircraft recip engines is contraindicated in that unique environment. My information on aircraft is at least 8 years old, so maybe that issue has been overcome in synthetics.
2) Extended automobile use. I was in direct contact with Mobil1 engineers in the late '90's, early 2000 period and at that time they indicated that Mobil1 10w-30 was acceptable for 15k miles, 20k max, provided that a Mobil1 filter was utilized, or other filter that was in the 10-20 micron range; 10-20 micron is the filtration for the DD's primary filter I believe. Since that time, they have marketed some synthetic oils that are for "extended use of 15k miles" and they recommend the new "extended range" Mobil1 filters for 15k miles". So it is now entirely acceptable to run Mobil1 for 15k miles (or one year max?), if you use their oil and filter that are rated for extended use.
P.s., the GM 3.8L engine can use the 5.7L filter, which is twice the size at the same price. So I run the Mobil1 5.7 filter on my 3.8L engine for even greater capacity.

3) Mobil1 has an extended range synthetic oil program for commercial marine engines. This program is coupled with periodic oil analysis and predicts up to 6,000 hour oil change ranges. It may also have a change on the run component, although I am not very familar with that. This of course may be oriented to the very large C series Cummins, or the 3 story high Pickering or Hitachi container vessel engines.

4) Gennies: My failover test for running my main's batts dead, is to always have the genny running, while starting the mains. Also, I may need to run the genny, while block heater. Since I start the genny in sometimes cold N. MI weather, I run Mobil1's diesel specific 40wgt synthetic oil. I use no oil during the season, so don't need to add oil, plus synthetic is great for the cold, as the viscosity is not noticeably affected.

5) Transmissions- I have spoken with Twin-Disc and they recommend using the same lube as runs in the engines. They have run tests on synthetics and have had variable results between brands- some good, some too slippery; see Mcycle trannies above. So I did run synthetic in my trannies, but I changed back to Texaco Ursa 40 (which is avail in Cheboygan, MI) and which the Hatt dealer uses. FWIW, I don't run that many hours per year, and my trannie fluid is so clean at the end of season that it is barely visible on the dipstick.

6) Advantages for synthetic: A) Synthetic oil viscosity is affected very little by cold temps, and so flows much better at cold starts and protects engine components almost immediately at start up. If you have every seen an old fashioned pushrod engine start with the valve cover removed, in cold ambient temperature, say 20-25F, then you would be stunned how long it takes for lube oil to reach the "top end". I have seen as long as 1-1.5 mins before lube oil reaches the rocker arms. On the other hand, synthetic is there in as little as 5 secs. I have owned a number of vehicles with oil pressure gages and synthetic oil rises to good oil pressure much more rapidly than mineral stock oil. B) Synthetic has a much longer life in the engine and on the shelf. Lube engineers at Mobil predict a 20 year usable shelf life for their synthetics. C) Synthetic is far more resistant to oxidation in normal use (no sludge) and under severe temperature conditions. When I was with Oldsmobile (oh, that long ago? yes) tests with synthetics showed just about zero wear in the valve train at 200k miles, esp. the cams that are the most sensitive.

So depending on the application, I am a major proponent of synthetics.

P.s., the only lubes I do not replace with a Mobil1 equivalent, are the lube in my Supercharger on my GM car, and the power steering lube in my GM cars. I am told by a lube engineer that those are good a lube as can be found.

 

[Boss Lady]

I agree on the superiority of synthetic oils, the Germans used them in WWII and their fighter aircraft could limp back to base with no oil pressure. The link I posted about filters is really good information on keeping oil clean. They have created an oil 'polishing' system to remove the stuff that causes wear and greatly increases engine life. I plan on putting a set on my engines.

 

[67hat34c]

most people think synthetic is something new but as you said the Germans used it in wwII, think it was from necissity as oil was in short supply.

 

[ThirdHatt]

LuckyDave, I agree on synthetics for use in just about everything except our old Detroits but we have something else in common! My current racecar is also a 944 Turbo S chassis with a pro-built (Eric Barrett) 2.6L GTR engine producing 507hp on the dyno with a full fiberglass widebody. Mobil 1 15w50 ONLY in the crankcase, 968 6-speed with a Porsche Motorsports 993RSR clutch and 996RSR Limited-Slip Diff with Redline Synthetic gear oil. It's set up as a GT-3R PCA Club Racer in full "Rothmans" guise. Who knew there was a fellow Porsche guy other than MikeP996 (now just MikeP)!