INSTRUCTOR: John Hallen
Oil -- What are you putting into your motorhome or tow vehicle. When you go to Wal Mart, can you buy off the shelf? What about diesel -- and turbo diesel?
SAW = Society of Automotive Engineers. Sets weight classifications. Non-profit standards setting. API is American Petroleum Institute, they set quality standards.
Just in past year, the classifications have changed. So beware of "sale on oil" signs, because it may likely be a sale of outdated oil. It may be a bargain, but not suitable for your rig.
API "SJ/CD" is current standard. Don't buy anything with "less than" SJ. Can use SJ on any vehicle, but can't use "SH" oil on many 1999 vehicles.
Next letter is "C" which is "commercial" or heavy duty. Last letter, "D" is latest in series.
Not all oils work in diesel engines.
"SAE 5W-30"
The "W" means winter. The lower the number before the "W", the easier it will pour in cold weather. If you're in Arizona, 15-40 might be better. It won't break down as fast in hot temperature. Multi-viscosity oils involve a tradeoff. If you're using a particular number use same when you add oil.
Oil puts friction in your engine. The thicker the oil, the less fuel economy -- but the tradeoff in terms of engine life. Some mfgrs say use 5/30 to get you better fuel economy -- but the tradeoff may not be worth it in terms of engine life.
"Energy conserving" -- additives which guarantee at least 1.5% better fuel economy. These are teflon, graphite, or silicon. -- all there to make things slippery to get better fuel economy.
"Energy Conserving II" -- means you get at least 2.7% more fuel economy. This means "friction modifyers".
Instructor says additives are "good", and help engine as well as
You get what you pay for in engine oils! The cheaper oils are cheaper for a reason.
Do NOT add friction modifyers (e.g., Slick 50) when engine is new -- b/c engine won't break in. First 5-10K, rings won't seat -- and you'll have an oil burning engine. Don't add syntetics or additives while under warranty.
5 yrs ago wouldn't have recommended synthetic oils. Now they are quite good -- but so good that can't use it until engine is broken in.
Service intervals. Regular duty versus severe duty. Regular duty is freeway in moderately warm weather with no dust. Virtually no one is "regular duty". But that is only to sell cars. You should ALWAYS consider you're in heavy duty/severe use. So change oil at the "heavy duty" miles rating. Should definitely change oil filter at each oil change.
Change diesel engine oil more or less than gas? No difference.
Park MH for winter, you have acid in oils, and they tend to corrode. If you change oil before storage, you get condensation which causes corrosion. For this reason, change at the beginning of season. Best solution would be to change at end of season, and again at the beginning of season, but that's probably impractical as well as expensive.
Don't run the engine every few weeks during the winter. [but catch 22] If you do that, need to drive it a long way. You get condensation in engine, causing rust -- push rods, rocker arms, cam shaft. Old myth. Another is let the engine warm up in winter -- Start it and let it run while you have a cup of coffee. Worst scenario is starting cold engine in winter. More wear on startups and long idling periods. If you do start it, run for an hour. If possible run air conditioner during the winter too.
Diesels -- less harmful to let it run than to start it. Block heaters help a lot. Diesel conditioners are primarily to let the fuel flow better. .
Alll gas is not the same. Cheaper gas stations often buy the better gas when there's an abundance of it. But the quality is uneven. Chevron additives are good. Higher octance, less knock in engine. He uses low octane fuel, unless ping/knock, which requires moving up. Octane is more important in hotter temperatures. Hot air offers less oxygen, so need better quality (octane) fuel. pinging hurts engines.
Synthetic Oils
Additives break down and you can't see it. Thus you can't go by a continuing "clean looking" oil.
Synthetics work well under both low and high temperatures. Better for starting and driving in cold temperatures. Less evaporation. Less viscosity change with temperature swings. Works well in all temps. Friction modifyers means more horepower, better fuel economy.
Synthetic Oil Disadvantages: Poor break in qualities. Don't use it while it's on warranty. Higher cost. 25K oil change. Can't mix w/regular oil or w/other brands. Okay to drain and go back. [Note: Other classes insist synthetics need to be changed with the same frequency as regular oil.]
Antifreeze -- 50/50 108 degrees. 3 degrees for every pound of pressure. Thus a 15 pound cap = 45 degrees more. But if radiator cap not sealing well, you just lost 45 degrees of boiling. Radiator caps not sealing and thermostat are the two most common problems w/cooling system.
Need for changing coolant every 4 yrs or 60K (kms). Coolant may look clean, but it's starting to do damage. Chemical called back flush which can take out scales. Needs to be flushed before re-fill. Not a do it yourself project.
Hose clamps. Only use worm drive hose clamps -- not sprig, srew tower or twin wire types.
Many thermostats are double stage -- if you have one of these, don't use a single stage thermostat when you change it.
Note: We subsequently had a note from a reader who takes strong exception to some of the above. His note to us states in part:
"I just finished reading subject article on engine oils and felt I had to contact someone.
For openers, the latest API classification for engine oils is not "SJ/CD" as stated. It is, in fact, "SJ/CH". The CD classification for diesel oils is very old and seriously outdated.
Then we come to "SAE 5W-30". The statement is made that, if you're in Arizona, 15-40 might be better. It won't break down as fast in hot temperature. Multi-viscosity oils involve a tradeoff." First, engine oils don't "break down" per se. They do oxidize from being exposed to high temperatures over prolonged periods of time, but this has nothing to do with viscosity. All oil will get thinner the hotter it gets. To minimize this thinning effect viscosity index improvers are blended into the oil. Thus, a 5W-30 oil will pour like a 5W oil when it's cold and will retain the thickness of an SAE 30 oil when it's hot. The same rules apply to the 15W-40 oil. Making a statement to the effect that multi-viscosity oils involve a trade-off without indicating what that trade-off might be is just plain irresonsible. The fact of the matter is that virtually all gasoline and diesel engine manufacturers recommend multi-viscosity oil in their engines.
The statement that teflon, graphite, or silicon (which is sand) are used to make "energy conserving" oils is just pure baloney. The truth is that the friction modifiers noted in conjunction with "Energy Conserving II" are what is used in all "energy conserving" oils.
Any instructor who says that additives are "good" just doesn't know what he's talking about. Any oil which meets API Classification SJ/CH already has all the additives it needs, no matter how much or how little it costs.
When the author discusses synthetic oils he really displays his ignorance. "5 years ago wouldn't have recommended synthetic oils. Now they are quite good--but so good that can't use it until engine is broken in". Mobil Oil has been selling synthetic oils for over 25 years. When the Alaskan pipeline was being built (a lot more than 5 years ago) Mobil supplied synthetic lubes for all of the equipment used to build it. That included engine oils, transmission oils, gear oils, hydraulic oils, and greases. The statement that synthetic oils are now so good they can't be used until the engine is broken in is also false. There is no valid reason for not using synthetic oils in an engine from day 1. In reality, however, engine manufacturers are not going to use synthetic oils in new engines because of the cost factor. And when a motorhome purchaser takes possession of his new motorhome it is likely to already have several hundred miles on it and is "broken in".
"Park MH for winter, you have acid in oils, and they tend to corrode. If you change oil before storage, you get condensation which causes corrosion. For this reason, change at the beginning of the season. Best solution would be to change at end of season, and again at the beginning of the season, but that's probably impractical a well as expensive." Now what does all that mean? The correct recommendation is to definitely change oil and filter before storage. Then, don't dump quarts (or gallons) of brand new oil in the spring. Any condensation which has formed in the engine over the winter hasn't affected the oil at all and any corrosion caused by that condensation has already occurred. Just start the engine and drive the vehicle until the engine is fully warmed up (it will take about 20 miles of driving) at which time any condensation which has formed in the engine will be evaporated and driven off. NOTE: The engine temperature gauge (which only measures coolant temperature) can indicate normal operating temperature while the engine oil is still cold. The engine isn't fully warmed up until the engine oil temperature has reached its maximum operating temperature.
Synthetic Oil Disadvantages: Poor break-in qualities - false, as already noted. Don't use it while it's on warranty - also false, as engine manufacturers can't deny warranty claims based on use of synthetic oils. Can't mix with regular oil or with other brands - absolutely false with no basis in fact at all.
I hope I've made it clear why I was so upset when I read the posting. I was a lubrication engineer for many years and was confronted on a regular basis by old wives' tales, myths, and just plain bum dope. Please feel free to contact me if you have any questions."