Mobil 1 and other Synthetic Oils

I read on this thread about 'abused engines' and one form would be 'prolonged high speeds'. We normally drive to Florida, roughly 1000 miles, between 14 and 16 hours at between 70 and 80 mph, straight through. Is this considered 'prolonged high speeds' or are we talking over pedal to the floor sustained driving ?

Thanks, Nick

That was my recollection too. The path of the air was thru the oil - the air entered the top outside of the filter housing, and had to do a U-turn into the oil bath and up thru the center of the housing to the throat of the carburetor. Any dust particles got washed into the oil - as long as you kept the bottom of the housing filled to the proper level. And boy was it a mess to "change" (empty of oil, clean the silt/oily dust particles out of the bottom, refill with frech oil). But not as much of a pain as the canister-type oil filters.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Absolutely not! (unless your in low gear). Pedal to the floor or - "close to the redline" would be more appropriate. We do the same trip to FL ave.

JB

Or sustained close to (or above) redline speeds where the bearing babbits are being hammered, even without metal-to-metal contact, and with normal operating temps, or where conn. rod fatigue induces crack growth due to square law stresses.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

I agree, but does this happen in European car engines overseas? or are they "built" better? They run on many parts of the AutoBahn just a few hundred RPM below redline for like a few hundred miles at a time. My friend in Germany has a U.S. spec 1996 BMW 3 series. I was just there earlier this summer and I asked him if he drives like this all the time - meaning 6000 RPM. He said yes, most others do too. But this is a U.S. spec BMW - I noticed the speedometer read 125 MPH (NOT kph) most of the day. The car has

Thanks for all the feedback. I usually get similar mileage on my trip, between 23 and 24+. I maintain it well, it's got 199.9k miles on it.

Nick

Whatever the merits of the various arguments, we need to dispel a myth about "European Autobahns".

Max speed limit rules vary across Europe (even if we confine ourselves to the European Union, now 25 countries), but the legal max tends to be 130 km/h. In Britain it is 70 mph (112 km/h).

In Germany there is, indeed, no legal maximum, but there is a government-recommended limit of 130 km/h. I have this notion that if you are in an accident over that speed the insurance company takes that into account, but I am unsure of that. Furthermore, many stretches of German motorway have specific limits, such as

That is not to say that people don't drive high speeds. I have been at 120 mph on quite a few occasions in Germany and Belgium (where speed enforcement is famously patchy, especially on the southern motorway through Wallonia), but I wouldn't risk it anywhere else.

Your friend's sustained 125 mph over several hours is an extremely rare occurrence.

I think that for most modern cars [even American ones.. :-) ] with engine sizes of 1.6 litres and up, cruising at 90 mph isn't stressful (in the right gear, of course). Even for 1.4 litres this should be quite manageable over the longer term.

DAS

I'm thinking that the air intake took a u-turn at the surface of the oil. While the air reversed direction, because of momentum, the dust particles went straight into the oil.

WVK

Wayne Van Kirk wrote in news:5mIYc.11608$ snipped-for-privacy@newssvr24.news.prodigy.com:

Nope through the oil. KB

Are you sure?

"Oil Bath Air Cleaners ENGINE OIL Oil bath air cleaners (fig. 1-38) draw air down a center tube where it strikes the surface of oil in the oil reservoir. As the air strikes the oil reservoir, most of the particles in the air do not make the 180-degree-upward turn. The dirt particles remain trapped in the oil. As the air continues upward and passes to the filter element, the smaller particles that bypassed the oil are trapped. The air keeps the filter element soaked with oil by creating a fine spray as it passes the reservoir. The air then makes another 180-degree turn and enters the intake system of the engine."

That may be correct. There was also some metal spongy stuff - much like a Brillo? pad - that filled the housing in the path the air made to the carb throat. It was usually wet with oil. The idea probably was that that stayed wet with oil either from being pulled by the air flow and falling back down, or just from simple sloshing. Kind of the same principle as the K&N filter, but more 3-D than two dimensional like the K&N, relying more on a think layer of oil rather than finer media only slightly damp with oil to capture the particles of dust.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

That could be construed as prolonged high speed

Depends. If the vehicl;e is running close to max gross weight, or has a roof rack running into a head wind, you could be loading the engine enough to cause a problem, just like towing a trailer. Today's vehicles are geared pretty long for mileage - my TransSport runs less than 2000RPM at 100KPH (60mph), and at that speed even the 3.8 liter engine is not producing much more power than absolutely necessary. The engine tends to lug a bit.

So, it does not necessarily fall into "prolonged high speed", but can , depending on the vehicle and conditions.

No, the air went through an oil soaked mesh filter, where all of the air came in contact with an oiled surface. Kind of a big "kurly kate" potscrubber, soaked in oil. In effect, the air was being drawn through oil with "bubbles" in it.

So this is wrong?

"Oil Bath Air Cleaners ENGINE OIL Oil bath air cleaners (fig. 1-38) draw air down a center tube where it strikes the surface of oil in the oil reservoir. As the air strikes the oil reservoir, most of the particles in the air do not make the 180-degree-upward turn. The dirt particles remain trapped in the oil. As the air continues upward and passes to the filter element, the smaller particles that bypassed the oil are trapped. The air keeps the filter element soaked with oil by creating a fine spray as it passes the reservoir. The air then makes another 180-degree turn and enters the intake system of the engine."

As former Counsel for a State agency that regulated such products I can report that several times we had to go after private chain oils sold at such venues because they consisted of Mobil's base oil without any, I repeat, without ANY additives! Be careful of the advise you give out.

Richard.

Richard - I'm curious. Was it a problem for legal (i.e., licensing) reasons, or for technical reasons. I guess I didn't know that a good synthetic base needed a lot of additives to make it a good oil. Or do they? (It's an honest question). Secondly, if no additives in a good synth base is a technical problem and not a legal one, why did the state get involved?

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Good questions.

We later passed a fuel quality law that let my state go after them for technical reasons. At the time it was enforced as a weights and measures issue because they failed to accurately identify the source of the product; the responsible party. At the time we lacked enforcement power to go after them just because it was mislabeled as to viscosity and grade. Most states lack the resources to enforce oil quality issues and the FTC has seldom taken any interest in this issue.

This base oil cost a few cents a can. It lacked any viscosity improver, lacked high pressure additives, lacked anti-oxidants, etc. Base oil is sold by Mobil and other venders as the starting point to formulate a product that meets industry standards. This is not to say that major brands have not put out junk now and then, but at least you know who to go after.

Richard.

No, not wrong at all. Some (heavy) dirt just jumps into the oil as the air makes the turn, the rest gets caught in the oil in the "potscrubber", and drips down into the bath. The air draws oil up into the "potscrubber. Gotta see one to understand it. I've seen and serviced hundreds of them..