Driven

Nov 13, 2008 - The car nut's guide to oil

As a member of  a few automotive forums in my day, one question that always pops up is "What oil is best?" ad nauseum. Ad-freaking-nauseum.

So I thought I'd post up some information for people actually, um, interested in learning how to make the oil choice that's best for you.

You'll hear about used oil analysis. It's one of the best ways to find out if an oil is acting in a desired fashion in your engine under the conditions it's being driven in.

The factors affecting oil are the engine itself, the outside environment in which the engine is operating, the state of tune of the car, the air and fuel filters used, the quality of the fuel used, and the driving conditions of the vehicle....i.e. frequently driven, short trips, long trips,etc.

Here's an example of a Used Oil Analysis for a Subaru Legacy GT:

So here's a primer on how to read these:

I've learned from alot of people at bobistheoilguy.com and reading alot, but I'm by no means the expert source.

basically, the numbers (for the most part) represent parts per million.

I.e. Iron 4 = 4 Parts Per Million of Iron.

Typically, you are looking at Iron, Lead, and Copper. These represent some of the main components of your engine for which you are monitoring wear related to lubrication. A VERY general guideline for these numbers is 1 PPM per 1000 miles...some cars wear more, some less, naturally. So you need to get a sense from trends in the same engine class or same exact engine.

Molybdenum, Calcium, Zinc, and Phosphorous tend to be your additive packages. These represent what makes this oil work. Some oils will have very little molybdenum but high calcium, zinc, and phosphorous. Others will rely much more heavily on molybdenum. I won't say any of these are important on a UOA except that if you find an oil with a particular additive package that works very well in your car (or very poorly), you should probably stay with similar oils.

Manganese is an interesting one. Rarely see it, but if you do it often represents a fuel dilution problem or traces leftover from fuel.

Silicon, Sodium, and Potassium - These are the usual warning signs. Silicon is representative of a few things....in a newer engine, or an engine with recent work, silicon will enter the oil from new silicone-based gaskets or sealants. In a broken-in engine, Silicon will typically be present as a result of air intake (dust/dirt has silicon in it). Excess silicon in the oil will act as an abrasive to metal parts inside the engine. Typically, a high silicon content will correspond with high iron, lead, and copper readings and will represent poor air filtration, or unfiltered air entering the combustion chamber. When high silicon is present and wear numbers are increased, it can mask problems relating to lubrication.

Potassium and Sodium are something else. Potassium in high levels indicates coolant in the oil. Red warning lights. Sirens. Coolant will destroy oil and your engine....when you get coolant in the oil, your engine wear will increase dramatically. A little coolant may have no effect. But sometimes a UOA will show increased potassium and you'll know your head gasket is leaking before major problems occur.

Sodium can indicate the same, or in lower quantities can be a by-product of the oil additive package. Unique analysis needs to take place to discern.

Ok, so we've tackled the metals. Let's move on.

CST and SUS viscosity tests represent....engine oil viscosity at operating temperature (around 200-210 degrees fahrenheit). The oil analysis above shows a "range" next to the tested value. The range in this instances represents what is considered a 30 weight oil. Reading this analysis shows that the oil viscosity was still a 30 weight. Why is this important? Some oils "shear", or become less viscous at operating temperature after use. A less viscous oil will typically protect the engine less against heavy loads and higher temperatures. This will result from the breakdown of the oil through fuel (we'll get to fuel), water, or the engine breaking the oil down.

Other oils will "thicken" and become more viscous. This is just as bad, as the oil thickening means that it's thickening through contaminants or de-graded oil. When an oil thickens alot, it typically means sludge has began forming.

Oils can shear or thicken and be just fine. But it's a sign of either other problems (i.e. fuel or water causing problems) or the oil not withstanding the pressure the engine is putting on it. Once an oil begins to shear or thicken, you usually don't want to be running it for thousands more miles.

Next up is flashpoint. This represents, effectively, the ability of the oil to withstand heat. It also represents the quality of the oil basestocks, or the base petroleum/molecules it's made up of. A high flashpoint will show that the oil sample analyzed is made up of high quality oil and has not been degraded. A low flashpoint (below, say, 370 degrees fahreneheit) will represent either a low quality oil, an oil degraded by fuel or water contamination, or a very broken down oil. Again, this measure helps show the quality of the oil and how it is withstanding your engine's treatment.

Fuel, antifreeze, and water - Fuel contamination occurs primarily during cold operation. Oil lubricates the cylinder walls so the piston can move up and down. Fuel is squirted into the cylinder. Combustion occurs....but some fuel gets into the oil and stays there. It burns up out of the oil during normal operation, but some engines dump tons of fuel into the oil and some people don't drive enough to burn all the fuel off. Fuel contamination breaks down the oil additives, viscosity, flashpoint....it dilutes the oil. This is one of the biggest reasons it's so important to drive the car at operating temperature for 10-15 minutes on a regular basis.

Water is similar.....metal, in cold weather, has condensation form on it. The condensation gets into the oil. It turns acidic due to the environment it's in. The acids break down the oil. The way to prevent this is to burn off the moisture frequently.

Antifreeze would show up as potassium/sodium as well, usually. Already touched on it.

Insolubles - Just like it sounds, the amount of the oil sample with things that are not dissolved. This is a measure of oil filtration. A high level of insolubles will mean your oil filter is not working well, and the insolubles start to become so prevalent that they increase engine wear.

TBN - Total Base Number. This represents the amount of "active additive" left in your oil, or in other words your oil's hit points. (Yeah, that's right, i said it). Most oils start with a TBN between 7-12. A high TBN is usually from an expensive oil with ALOT of additive in it. TBN remaining in the oil represents how much longer you can expect your oil to hold up in it's current operating environment.

If you drive a car for 10,000 miles with an oil with a starting TBN of 10, and it's 3.0 after 10,000 miles, you can probably make it to 11,500 miles will active additive left. Maybe more. A TBN of 1.0 is considered a "dead oil"....you don't want to run it any longer.

There's alot more to this system than just what's above, but that's a primer.

Oil sump capacity comes into play. If a car has a 10 quart capacity and reads 10 PPM Iron after 3,000 miles, that means that even though it has a huge capacity it's got alot of iron in it (Parts Per Million is distributed among the entire oil capacity, and therefore that car has the equivalent of 20 PPM in a 5 quart sump after 3,000 miles....which would be considered higher than desirable).

Make-up oil is also important. Every time you add oil, you are adding fresh oil with all of it's active additive (TBN). This helps to "refresh" all the oil in your engine.

I could go on, but I think that should cover you for reading these reports.

The best thing to do, if you want to commit the time and money, is to take multiple samples on the same car. That way you can see trends.

To give an example of why that can be important: Some GM engine owners became very concerned when their cars always had high Iron in the UOAs. They switched oils, air filters, did tune-ups, replaced oil filters. Same results. Enough trending showed that those engines simply spit out iron. It was just the way the engine was

So....you take this information, maybe you visit bobistheoilguy.com and find some UOAs for your engine in a variety of conditions. From this, you'll get a feel for what oils are working well in an engine and in what conditions. Some oils do better under certain driving conditions than others.

Now....how to actually pick an oil for your car and driving conditions? First, manufacturers recommendations. Does it recommend a 5w30? Then a 15w50 probably isn't going to work well. but a 0w20, 5w20, 0w30, 5w30, 0w40, and 5w40 are very reasonable.

Synthetic vs. Dino? If you drive your car hard. If your car has serious performance aspirations. If you do lots of short trips. If you don't drive your car for days at a time. If you live in a very hot climate. If you live in a very cold climate. If you intend to keep your car for a long, long time. Go synthetic.

Synthetic oils are more stable over a wider range of temperatures. The oil molecules are more homogenous in size (and typically smaller)....which means they flow better on a whole and especially in small spaces where there is lots of turbulence. They have greater resistance to breakdown as a result of all sorts of forces. And they typically have more robust additive packages to protect and lubricate your engine. You can get decent, cheap synthetic for as low as ~$3.50 a quart at it's regular price at walmart as Supertech 5w30 synthetic. If you are using regular "DINO(saur)" oil, at least switch to this.

Further, synthetic oil can extend your oil change intervals. It lasts longer. Running synthetic for 3000 miles or even 5000 miles may be appropriate, but in 98% of cases it's throwing out money. The picture above of AMSOIL SSO 0w30 is the oil I've run in my Civic SI for 15k miles without a change....and when I did change it, I had an analysis done. Guess what? My engine was running like a top....and the oil still had a few thousand more miles left in it. Wear levels were far below average for the engine.

But which brand for your car? What exact viscosity? It's hard for other to answer this for you. Almost all mainline synthetics are great lubricants. Some do better than others. Here's a few for 95% of applications I'll put the JoeFromPA stamp of approval on:

Mobil One 0w40

Redline 5w40

Pennzoil Platinum 5w30

AMSOIL SSO 0w30 (not a mainline oil)

Castrol Syntec 0w30 (european formula, called german castrol)

Renewable Lubricants 5w40 (not a mainline oil)

Among others...

Good luck in your search. A quality oil provides piece of mind and prevents problems when you are stressing your engine out or keeping it for a long time. If nothing else, you'll be maintaining the engine to a great level for the next owner :)

Joe

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Nov 13, 2008 - Searching for "the one"

Any car enthusiast can spend an eternity trying to find a car tailor made for their needs. Many do this by endlessly car hopping: expensive but allows for the owner to experience many vehicles in-depth within a short period of time. Others own multiple vehicles, trying to specialize each for their needs. Maybe a truck, a family hauler, and a sports car. The benefits are obvious....the sports car doesn't have baby vomit and spilled milk, the family hauler isn't asked to clip an apex, and the truck doesn't need to haul the family to Aunt Milly's holiday re-union 12 hours away.

But many of us don't have space for 3 vehicles (or the garages needed to properly house and service them). Many of us have spouses who object to the idea of insuring 3 vehicles before being much wealthier than current bank statements suggest.

People like that (me included) search for the "one". The one car that can do it all. Schlep clients in comfort. Look sharp cleaned up. Perform family duty with admirable ease. Haul stuff. And Ass. And yet provide great steering feedback, a firm push in the back when desired, a great sound at start-up. Great seats, a friendly manual transmission, a controlled ride, satisfying handling. Decent fuel economy a plus.

Maybe a few luxury touches? Power memory heated seats. Leather. Quiet highway cruising. The equivalent of a business class international flight.....when you leave, you feel refreshed (or drunk).

The car that's currently meeting these specifications for me is the e39 5-series. That's the 1997-2003 BMW 5-series. Pictured above are examples of a silver 2003 M5. The interior shown is of a 2001 M5 with caramel leather. How gorgeous is that? How unique?

Why the e39? It's in my price range. It's look is classic and eloquent and never overstated. It offers a 4.4 liter v8 putting out ~290 HP and ~320 TQ, combined with a 6-speed manual. 4-doors with real-life spaciousness....the car is very appropriate in size standing next to it. It's right-sized.

The germans did crazy stuff like filling door cavities with foam to reduce resonance and noise on the road. Tuning the chassis to resonate at a different frequency than the engine and tires....so that they don't amplify each other and annoy passengers. The chassis was actually so stiff it remained un-changed when BMW launched the 2004 5-series.

But falling in love with writings about a car is different than loving a car. You need to drive it. So I did. And everything they said about it was true. Satisfying each need I placed upon it, performance wise and comfort.

So my search for the e39 for me has commenced....it might be a few years, and that's fine. I'll bide my time and drive the hell out of my 06 Civic SI 25,000 miles a year.

So what's is your "one" car? What drives you? Or how many cars have you gone through without finding satisfaction?

I accept the fact that I might buy an e39 5-series one day and find myself longing for something else...but at least it will have already depreciated.

Joe

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