Will switching from Synthetic to Dyno oil harm my engine?

FWIW, that is the message I get from my gear-head younger brother. He tells me it leaves crusty carbon that just won't dissolve with anything throughout engines.

Mike

My $.02 worth... I have never used Amsoil but it is a mainstream product. Not magic, I'm sure, but at least some independent references give their products high ratings. (See, for example,

for a comparison of oil filters.) My trusted guys at the local NAPA recommend AMSOIL oil, but I've been using Mobil 1 currently. Other than the proselytizing, what is your complaint with AMSOIL?

Mike

I have changed a few of my cars from regularly changed dino to synthetic or (in the case of my 220K mile turbo Volvo) to synthetic blend. I do one change with a single quart of synthetic added to the rest of the usual Valvoline 5W-30, and change to synthetic 1000 miles later. The oil always comes out opaque black after 1K miles... but maybe the higher detergency is a myth. If you are wondering whether the changes were regular enough, consider that the original turbo has been on the Volvo for 20 years, while most of the Volvo gurus say 100 - 150K is the life expectancy.

Mike

Naw, it isn't.

We know nothing about how "independent" this source is.

...and will be happy to sell it to you, I'm sure.

Fuhgeddaboudit. Go hit googlegroups.

DS

Latest inductee into the "bad oil of the year" club, eh? We've heard the same ghost stories about Pennzoil, Quaker State, and probably every other major brand at one time or another...

Here's some of the text of the "high rating" Scamsoil filters are given by your "independent reference":

" The AMSOIL company recommends changing their filters at 12,500 mile or 6 month increments. Based on their numbers, this seems reasonable. They have better capacity and stronger construction which should allow them to achieve longer change intervals. Since AMSOIL filters have been recommended for these intervals for about 20 years, it seems reasonable that they know what they're talking about."

Have not.

Rotella T, Delo-400, Mobil Delvac ... those are your MAINSTREAM diesel oils. Just visit any truck stop to see for yourself. Rotella Synthetic 5w-40 is very rare in truck stops as is Delvac 1300.

Yes, old is old. I was referring, but not clearly, to newer vehicles. (except Toyota V6's 8) )

Google will get me every rumor and troll and crackpot idea around. That was the complaint you have with my Havoline report, although my brother is *way* up on my automotive source list.

I respect your opinion more than those of random hits. Really!

Mike

Yep - and the numbers they were talking about were in the preceding text. "For those of you who just want to know what's best, here's a breakdown of the top 3, in my opinion. Mobil 1, Pure 1 and AMSOIL provide the greatest filtration efficiency in the tests I've seen. Mobil 1 and Pure 1 both achieved 93% overall filtration efficiency on the SAE HS806 test. AMSOIL scored a 94%."

If AMSOIL *does* test well, can't you accept that?

Mike

I appreciate that; I meant see *my* previous answers to your question, via Googlegroups.

Sure, but we don't know that they do. The author says the Scamsoil filters did well in "tests he's seen". Jolly good, fine and well. Scamsoil filters have done poorly in tests *I'VE* seen.

AND,

Scamsoil changes their filters' build specs as often as every other filter maker does; today's results may not apply tomorrow and almost certainly won't apply this time next year.

AND,

Scamsoil's filter lineup includes a lot of different filters, too; I'm not willing to generalize the performance of any manufacturer's entire filter line by the performance of one item from that line.

AND,

Scamsoil makes enough dubious (and outright incorrect) assertions about enough of their products that I view them as an untrustworthy company.

AND,

I will not stop calling them "Scamsoil" until their hordes of pyramid-crazed, True-Believer salesdroids disappear.

Yeah, and I could just pee in the oil fill hole for free. Yer point?

While I don't deny that relatively inexpensive conventional oils are adequate for most engines, I simply do not trust the $.49/quart pisswater to have anything like a halfway decent additive package. When I use a conventional oil, I use one that has a good reputation (Castrol, Valvoline, etc.) and that I know will have the same additive package (or will improve over time) every time I buy it, rather than some different random lowest-bidder blend stuffed into the same generic bottle at each buying cycle.

"

And in fact it DID test well in that LS-1 long-term test (I belive its linked somewhere from bobistheoilguy.com). But, in the long haul it didn't hold up quite as well as Mobil 1 (excessive viscosity increase, and lost its TBN much faster despite starting at a HIGHER TBN number than Mobil 1).

And since they are very tight-lipped about the formulation, you never know when they might change the additive packages for the worse without re-labelling (although being "name brand" doesn't guarantee against that either- witness the Valvoline Max Life fiasco where they changed the forumlation radically for the worse about a year after its introduction with a very good package.)

And I HATE the direct sales BS.

I like this Daniel Stern guy. He has great information and he's a good writer.

Dave

On 12/21/2004 2:53 PM US(ET), David Geesaman took fingers to keys, and typed the following:

He didn't look too intelligent in "Home Alone" 1 and 2. :-)

Bill

It could probably be argued either way. VW may well be the volume leader in passenger diesels in the US (no, I don't have a single number to back this up). They recommend synthetic oil for their TDI's. So, for passenger car diesels, I would say synthetics have caught on.

"Philip" wrote >

Oh but it has. Not only are specific synthetic oils becoming the preferred lubricant for diesel engines, the service intervals are generally longer than for petrol engines. VW/Audi petrol engines can run up to 20,000 miles between oil drains while their diesel engines can run up to 30,000 miles. Similar intervals for GM/Opel/Vauxhall. Mercedes and BMW have the same potential drain intervals of up to 15,000 miles but practical experience has shown these vehicles to have average intervals of around 12000 miles for petrol engines and 14,000 miles for diesel. The discrepancy between 'potential' and 'actual' is due to the flexible and monitored nature of all these vehicles service intervals. Mercedes is now specifying even better oils than before in their newest cars and have similar service intervals to VW.

You should also note that modern direct injection diesel engines are much cleaner than your old Nissan indirect injection engine. Also ultra low sulphur fuel is much cleaner and produces less soot and acid which accounts for some of the improvement in diesels, allowing them to overtake petrol engines in their service schedules by quite some margin. It is remarkable that in tandem with this improvement is a remarkable improvement in specific power output, refinement and economy. All as a result of tightening exhaust gas emission regulations that dictate new technology and innovation.

Huw

Tractor engines are now commonly up to 500 hour intervals, which is equivalent of 15,000 miles in an average road vehicle, on dyno oil which meets just API CH4 or MB228.3 long drain specifications. No doubt that could be almost doubled if synthetic oil meeting MB228.5 were used. Certainly +50% is pretty safe if the filter was changed half way.

Huw