Synthetic oil?

1. I haven't experienced greater leakage with synthetics than with mineral oil. That isn't to say that synthetics won't leak slightly more, but from my experiences (and tests I've read) it's not as overblown as some of the anecdotal reports I've heard.

2. Cold weather startup is fantastic, even with my stock 6 volt system in subzero weather. This means no block heaters or crankcase heaters.

3. I change oil at standard intervals. I figure that synthetic oil costs me about $20 a year extra for two oil changes. That's cheap insurance. I do NOT regard synthetics as an excuse for not changing oil, or changing oil late. Incidentally, the "dirty" oil (and internal engine parts) stay extremely clean, so I don't understand the concern about grit.

4. In my other life, I work extensively with stationary automatic standby generators, the engines of which have a lot in common with N applications--they operate at relatively low, constant engine speed under continuous load, and often sit unused for weeks before being expected to start immediately and load seconds later. Most of these generators use Mobil 1 (it's the factory pour for some). I can guarantee that these engines, broken down after many hundreds of hours, look astonishing. Many of the internal parts look new, and the inside surfaces of valve covers look like new, without the slightest trace of sludge. Ditto for oil pans. There is no way anyone can tell me that engine life isn't extended by the properties of synthetic oil, changed regularly.

5. The actual properties of thermal breakdown of synthetic oils aren't particularly relavent to N-series engine, or other consumer engines, for that matter. First, I don't believe I'll be seeing a lot of flathead Fords with updraft carburetors at Indy this year. And secondly, every synthetic I know of breaks down at much higher temps than mineral oils. If a synthetic oil fails due to temperature, it's still going to have occurred later than with standard oils.

I'm not saying that N owners need to change to synthetic, but I can't agree with the posts that maintain that there are no advantages for this application. There are.

On these old engines, the first quirk that comes to mind is leaking. Synthetics are superb at it. They will take a damp spot and convert it into a runny spot in short order.

They are also a nightmare with friction systems like limited slip clutch packs, wet clutches, bands, etc. You can get things so slippery they will not engage (grinding synchro rings in manual transmissions is not uncommon), or they will not be slippery enough giving you chattering clutch packs. It's hard to find one that works just right for this sort of application.

There are some temperature issues to that may affect these old tractors. There are two main types of synthetics (don't remember what they are called). Both break down at higher temperatures, but one of them breaks down completely and abruptly when overheated, and the overheat temperature is not that far off from a hot engine. Smokey Yunic's book discusses this aspect quite well. I have seen this breakdown on some motorcycles running synthetic. The damage isn't pretty.

Remember too, grit contamination is a major player in tractor wear, and these N's can't filter the oil worth a hoot. So you get tremendous grit buildup in the oil, which grinds the parts away.

I'd be willing to run a synthetic in my N, but I don't see the need to switch. Regular oil does just fine for me in this application. I reserve the synthetics for different uses in my case.

As for Slick 50 and such, snake oil tends to describe them best. Just look at their various TV adds. I really liked the one where a couple of ya-ho's added some snake oil, drained the crankcase and left the plug out. They swore the low oil pressure idiot light never came on, it was so good. Think about that one.

I think synthetics have absolutely proved themselves in modern motors, which are designed to use them and which have proper sealing, filtration and other characteristics which make them work. Their cost-benefit advantages really shine in high-mileage over-the-road applications.

For our kinda stuff? Nah. Not worth it. The extended oil change advantages are lost because the N motor will last longest with regular oil changes regardless of what's in the crankcase. It blows by, it's subject to oil dilution and condensation, some of the seals will not hold it back and (as Nolan says) the filtration system ain't exactly state-of-the-art.

I'll save the synthetics for the Peterbilt, with its quad filters and triple-lip double-up seals, where I can save some bucks. For the N, I'll stick to conventional motor oil.

As to Slick 50, Prolong, Motor Magic and all the others - bunch of hooey. 50¢ worth of motor oil and PTFE with a $25 marketing program. Don't waste your money. For what they cost, you can do an extra 3 complete oil changes, and those will do more for the life of your motor than any magical wonder-additive.

Take particular note that Quaker State, which owns Slick 50, is selling it under the provisions of an FTC ruling which found the majority of their previous advertzing claims to be without foundation.

llater,

llamas

In many cases, synthetic oil properties are a wasted benefit that the engine never sees or utilizes. If a person does regular short interval oil changes, and does not abuse the engine (no lugging, good tune, etc), a regular dino juice motor oil will do a perfectly adequate job of lubricating the parts and protecting them, and is never exceeded. The above and beyond benefits of sythetic oils would be wasted in this application.

It's kinda like planting 30 tomato plants when there's only two of you in the house to eat them. Oh you've got tomatoes! But you don't get a benefit from all the excess. You only eat so many tomatoes, the rest are wasted. Four tomato plants would have done just fine.