 Choosing the best motor oil is a topic that comes up frequently in discussions between motoheads, whether they are talking about motorcycles or cars. The following article is intended to help you make a choice based on more than the advertising hype.
Oil companies provide data on their oils most often referred to as "typical inspection data". This is an average of the actual physical and a few common chemical properties of their oils. This information is available to the public through their distributors or by writing or calling the company directly. I have compiled a list of the most popular, premium oils so that a ready comparison can be made. If your favorite oil is not on the list get the data from the distributor and use what I have as a data base.
This article is going to look at six of the most important properties of a motor oil readily available to the public: viscosity, viscosity index (VI), flash point, pour point, % sulfated ash, and % zinc.
Viscosity is a measure of the "flowability" of an oil. More specifically, it is the property of an oil to develop and maintain a certain amount of shearing stress dependent on flow, and then to offer continued resistance to flow. Thicker oils generally have a higher viscosity, and thinner oils a lower viscosity. This is the most important property for an engine. An oil with too low a viscosity can shear and loose film strength at high temperatures. An oil with too high a viscosity may not pump to the proper parts at low temperatures and the film may tear at high rpm.
The weights given on oils are arbitrary numbers assigned by the S.A.E. (Society of Automotive Engineers). These numbers correspond to "real" viscosity, as measured by several accepted techniques. These measurements are taken at specific temperatures. Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50 by the S.A.E. The W means the oil meets specifications for viscosity at 0 F and is therefore suitable for Winter use.
The following chart shows the relationship of "real" viscosity to their S.A.E. assigned numbers. The relationship of gear oils to engine oils is also shown. _________________________________________________________ | | | SAE Gear Viscosity Number | |_________________________________________________________| ||75W | 80W |85W| 90 | 140 | | ||____|_____|___|______________|________________________| | | | | SAE Crank Case Viscosity Number | |_________________________________________________________| ||10| 20 | 30 | 40 | 50 | | ||__|_____|____|_____|______| | |_________________________________________________________| 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 viscosity cSt %40 100 degrees C Multi viscosity oils are one of the great improvements in oils, but they should be chosen wisely. Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best. Very few manufactures recommend 10W-40 any more, and some threaten to void warranties if it is used. It was not included in this article for that reason. 20W-50 is the same 30 point spread, but because it starts with a heavier base it requires less viscosity index improvers (polymers) to do the job. AMSOIL can formulate their 10W-30 and 15W-40 with no viscosity index improvers but uses some in the 10W-40 and 5W-30. Mobil 1 uses no viscosity improvers in their 5W-30, and I assume the new 10W-30. Follow your manufacturer's recommendations as to which weights are appropriate for your vehicle. Viscosity Index is an empirical number indicating the rate of change in viscosity of an oil within a given temperature range. Higher numbers indicate a low change, lower numbers indicate a relatively large change. The higher the number the better. This is one major property of an oil that keeps your bearings happy. These numbers can only be compared within a viscosity range. It is not an indication of how well the oil resists thermal breakdown. Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendency for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. The flash point can be an indicator of the quality of the base stock used. The higher the flash point the better. 400 F is the minimum to prevent possible high consumption. Flash point is in degrees F. Pour point is 5 degrees F above the point at which a chilled oil shows no movement at the surface for 5 seconds when inclined. This measurement is especially important for oils used in the winter. A borderline pumping temperature is given by some manufacturers. This is the temperature at which the oil will pump and maintain adequate oil pressure. This was not given by a lot of the manufacturers, but seems to be about 20 degrees F above the pour point. The lower the pour point the better. Pour point is in degrees F. % sulfated ash is how much solid material is left when the oil burns. A high ash content will tend to form more sludge and deposits in the engine. Low ash content also seems to promote long valve life. Look for oils with a low ash content. % zinc is the amount of zinc used as an extreme pressure, anti- wear additive. The zinc is only used when there is actual metal to metal contact in the engine. Hopefully the oil will do its job and this will rarely occur, but if it does, the zinc compounds react with the metal to prevent scuffing and wear. A level of .11% is enough to protect an automobile engine for the extended oil drain interval, under normal use. Those of you with high revving, air cooled motorcycles or turbo charged cars or bikes might want to look at the oils with the higher zinc content. More doesn't give you better protection, it gives you longer protection if the rate of metal to metal contact is abnormally high. High zinc content can lead to deposit formation and plug fouling.
The synthetics offer the only truly significant differences, due to their superior high temperature oxidation resistance, high film strength, very low tendency to form deposits, stable viscosity base, and low temperature flow characteristics. Synthetics are superior lubricants compared to traditional petroleum oils. You will ha veto decide if their high cost is justified in your application.
The extended oil drain intervals given by the vehicle manufacturers (typically 7500 miles) and synthetic oil companies (up to 25,000 miles) are for what is called normal service.Normal service is defined as the engine at normal operating temperature,at highway speeds, and in a dust free environment. Stop and go, city driving,trips of less than 10 miles, or extreme heat or cold puts the oil change interval into the severe service category, which is 3000 miles for most vehicles. Synthetics can be run two to three times the mileage of petroleum oils with no problems. They do not react to combustion and combustion by-products to the extent that the dead dinosaur juice does. The longer drain intervals possible help take the bite out of the higher cost of the synthetics. If your car or bike is still under warranty you will have to stick to the recommended drain intervals. These are set for petroleum oils and the manufacturers make no official allowance for the use of synthetics.
Oil additives should not be used.The oil companies have gone to great lengths to develop an additive package that meets the vehicle's requirements. Some of these additives are synergistic,that is the effect of two additives together is greater than the effect of each acting separately. If you add anything to the oil you may upset this balance and prevent the oil from performing to specification.
The numbers above are not, by any means, all there is to determining what makes a top quality oil. The exact base stock used, the type, quality, and quantity of additives used are very important. The given data combined with the manufacturer's claims, your personal experience, and the reputation of the oil among others who use it should help you make an informed choice.
There are only 3 direct OEM tire sizes available for the Durango (235/75R15, 31x10.5R15 or 275/60R17 - for the R/T). Listed below are some "available" tire sizes that have the same approximate diameter (within .5") for proper + sizing of your wheels/tires without requiring any speedometer recalibrations.
Note: The above table refers to Light Truck applications and automobile tires may not have the same ratings and will not always perform to the same minimum requirements of a Light Truck tire. The table was constructed using Big Al's Durango Tire Calculator to find an equivalent tire size and then checking for availability of that size at the Tire Rack web site.
Tire Rack is one of the best on-line tire reference sites and has a lot of useful information on the fitting of new wheels/tires for vehicles. Of particular note is their "Wheel Rack", an interactive wheel fitment guide that shows what a particular wheel looks like on a specific make, model and year of vehicle.
The ABC's of ABS? from http://www.abs-education.org/abcs/abcindex.htm What Your Anti-Lock Brakes Do: ABS helps improve vehicle stability, steerability and stopping capability.It prevents wheel lock-up, allowing you to maintain better control of yourvehicle during an emergency braking situation.
How does the Anti-Lock Mechanism Work: When you step firmly on the brake pedal, the system automatically modulates the brake pressure at the wheels, adjusting pressure to each wheel independently to prevent wheel lock-up. Since the wheels don't lock-up, you have improved steering control of the vehicle and less chance of skidding.
So what's the difference between four-wheel (4WABS) and rear-wheel (RWABS) anti-lock brakes: 4WABS modulates the braking of all four wheels allowing you to make corrective steering changes while still braking. RWABS, found exclusively on light trucks, vans and SUVs, only modulates the braking of the rear wheels. While this does help you maintain directional stability and prevents the rear of the vehicle from skidding sideways, the front wheels "can" still lock up; especially if you attempt sudden steering changes while braking! If that happens, ease up on the brake pedal just enough to allow the front wheels to start rolling again to regain steering control.
How do you know when your ABS is working: In most cases you can tell the anti-lock brake system is operating because you'll notice a mechanical sound and feel some pulsation or increased resistance in the brake pedal. It's important to keep your foot on the brake pedal when you hear/feel this and continue to apply firm pressure.
DaimlerChrysler Computer Codes Getting the codes, from All•Par
If you have fuel injection, this works on most Chrysler, Plymouth, and Dodge cars made in the 1980s and 1990s.
The Codes
Notes:
For TBI engines, the injector's cold resistance should be between 0.9 and 1.2 ohms (specs vary with year). This is a peak-and-hold injector. With the engine idling the peak period should be about 1.2 milliseconds whereas the hold period will vary. If it's lower than this at idle, then the injector's shorted or there's a defect in the injector driver circuit. I've used the Z1 voltage to test for good power connections to the power module. I connected my OTC 500 multimeter from the battery's positive post to the ignition coil's switched battery terminal and measured the voltage drop using the bar graph to monitor peak voltages. Voltage spikes of around 200 mV to 300 mV are ok. Anything more means tv tuner cleaner time (or replacing the power module). Another thing to check is the maximum voltage drop during the priming pulse. With the old power module, I was losing about 2 volts across the circuit; the replacement is losing about 1/4 volt.
Note: Most paint codes come with color variations from the factory. This means that within a particular color, there will be distinct variations. For example, as of April 2000, there are three different White's - regular, blue and yellow, all within the PW7 paint code. Always work with your body shop to determine the correct paint for your vehicle.
Air Filtration & Efficiency (An official response from K&N concerning accusations made about their filtration products) To Whom It May Concern, especially Mr. George Morrison who has taken K&N to task with some very undocumented accusations.
GM Comment: We were spending upwards of $30,000.00 a month on paper air filters using them one time and then tossing them away.
Question: What was the total number of paper air filters used each month and how long was the service life for each paper element?
GM Comment: "... reusable air cleaners showed an immediate large jump in silicon (dirt) levels... etc.
Question: What is a large jump: What was the PPM count before the "reusable air filter" and what was the PPM after installation and use? What was the PPM with the foam and what was the PPM with the K&N?
There are allowable limits and without the facts it is impossible to comment.
However Regarding the silicone levels K&N has recorded over six years running, oil analysis from two Southern California transit authorities. This includes some 800 large diesel buses and 200 "Dial A Ride" gasoline vans. Oil samples were taken every 60 days and did not exactly match the changing or service of the air filter element! All air filters were serviced at 25" of water restriction. When running with paper air filters we did notice an increase of silicone as the element grew dirty some as high as 25 PPM. When the K&N elements were installed we noticed a drop to more acceptable levels (6 12 PPM) at the next oil sample test. Not once have we recorded any abnormally high silicone counts with the K&N elements. Average mileage per vehicle is 50,000 miles per year, 50,000 miles times 1,000 vehicles equals 50 million miles a year. Not one engine has suffered damage during this time while using K&N air filters. K&N did save the two transit authorities a lot of fuel, reduced their labor to change out the paper air filters (one K&N would last the same life as 3 paper elements) plus hundreds of thousands of dollars purchasing new paper elements.
For the record, K&N does not manufacture or specify any of it's air filters for the mining or construction industry. We do on occasion rebuild some very large and strange air filters for a lot of our customers. Rebuild, means that we take a dirty paper air filter, disassemble it and by using the old end caps and wire baskets we will rebuild the filter using the K&N filter media. Upon delivering the "rebuild" to the customer, he is advised that we will not vouch for the application or proper sealing of the element into his air filter canister. We have no way of testing the seals of the gaskets. We suspect this is the type of K&N air filters which Mr. Johnson used in his test.
Evidently, Mr. Johnson was conducting his own evaluation, which is good, as we do it on some things we source out. However, had K&N been on site or directly involved with the test, I'm certain the test would have been more favorable for Mr. Johnson and K&N. First off, you do not want to mix one of the oil impingement air filters (K&N or Foam) in combination with paper, especially paper safety filters. Try this simple test yourself by spraying your paper air filter element with a very thin oil or WD 40, WOW! That combination will lock up an air filter very quick, plus you could damage the paper filter media I'm not surprised that Mr. Johnson's safety filter clogged, but I am pleased it went a full half day. I would have bet one hour at most If you fit a new paper safety filter with a new K&N or foam outer filter, just remember any excess oil, and there will be excess oil, will be pulled off almost immediately into the safety filter and you have instant restriction.
Instead of using an inner paper safety filter, why not incorporate a foam or polyester pre filter on the outside of the K&N element? This combination has proven to be extremely effective operating in very dusty desert conditions. Offroad racers, operating in desert sand and fine silt beds, will use an oiled foam wrap or pre filter on the outside of the K&N element. Once the wrap is clogged it can be replaced in just seconds. Baja racers will change foam wraps at each pit stop and never touch the K&N set up during the entire 1,000 mile race. For mud and heavy sand, we recommend the polyester Precharger wrap. This is a fine denier mesh (similar to panty hose) that will deflect the sand and mud. Being of a very slick material, the Precharger will cause the dirt to slide off and not pack into the K&N filter pleats. Also, the polyester can be changed rather quickly.
What about efficiency of the filter or the filters ability to stop dirt? There are two acceptable tests used by the filter industry to verify the efficiency (actually just one test but with two grades of dust) SAE J726 F or C (fine or course dust). The exact mixture is detailed at the end of this report 100% efficiency is perfect but rare for any air filter that also allows enough air through for engine use. One major air filter manufacturer of paper elements has consistently advertised a 97% dirt free media filter for all its elements. This is very good, yet there are some others that claim 98 99%, but I have never seen one of their test reports. K&N has certified reports of 97.4% FINE for its four ply (four layers of cotton gauze) and 98.2% COURSE for the commercial 6 ply filters.
Incidentally, the U. S. Army just completed a 30 cycle test of the K&N air filter for possible use on helicopters operating in dirty dusty desert conditions. The 30 cycle test consisted of air being pulled through the K&N filter at speeds required by the helicopter jet engine for full power. At the same time, dirt is induced into the air stream per the SAE J726 C test procedures. When the restriction reached 25" of water, the filter was removed from the test chamber and serviced per K&N's instructions (washed re oiled). Again, the same element was tested and serviced over and over for 30 complete cycles. In the end the K&N was still operating with a 97% efficiency.
In conclusion, K&N has been manufacturing and selling the washable reusable air filter for over 30 years. To date, we have not lost one engine because of the filter media being inferior.
This website is in no way affiliated with Dodge or Chrysler LLC.
Dodge® and the Ram's Head logo are registered trademarks of Chrysler LLC. |
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