Best reason to use synthetic is in-grade stability and protection against heat. Good synthetics don't smoke at the temps that conventional oils do.

In fact, I remember reading that synthetics like Mobil 1 can stand over 450 degrees without losing their ability to protect the motor. For that reason alone I use it.

When the topic makers of luxury and sports cars ship those cars from the factory with synthetic in the motor you can be sure it's the real deal.

Can't beat any modern name brand Synthetic oil! I go by my vehicles oil life computer & change as needed. Its usually between 6-7.5K miles. Protects better in cold winter startups & hot weather towing my bike trailer! Engine internals remain spotless too! Dino oil is for the dinosaur age!

I change my oil every 3K, yea its probably overkill but its cheap insurance.

Two things. Non-synthetic oil will swell certain seals in older engines and a switch to a full synthetic could stop that and make the oil leak like crazy after the seals shrink (valve seals, specifically). It has nothing to do with being "thin" or anything like that, and in that case a synthetic blend oil is fine.

Diesel oil is also formulated for low-sulfur fuels, but gasoline still has a lot of sulfur which is one of the big mandates keeping diesel oil and gasoline oil separate. Always look for the manufacturer specification on the back of the bottle. If it doesn't say it meets that, move on. VW diesel oil is extremely specific and can be hard to find in stores.

After the first 30,000 miles I switched our Ram 3500 diesel to Rotella T synthetic. I had oil and filter changed every 10,000 miles. We were fulltime rv'ers towing a very heavy fifthwheel with that truck as well as doing all our sightseeing and normal transportation. We stopped traveling and sold that Ram at 107,000 miles. It still never used any oil between changes. I give credit for part of that, at least, to the synthetic oil.

@Mark Williams

You should have added one more myth.

The numbers classifying oils is it's viscosity grade at different temperatures, NOT weight as most call it. There is no such thing a a 30 "weight". There however a 30 "grade". The "W" actually stands for "winter" or colder temperatures. The first number is a multi - grade oil is it's viscosity grade on a usual cold start, and the second is it's grade at operating temperature.

It is also good to note that most engine wear is from that brief moment from when you start your engine to when the oil finally reaches operating temperature. This usually takes 10 to 15 minutes. Even 0 grade oils are too thick on start ups, but they take less time to get to operating temperature.

I agree with all the above except for I question number 8. You can't always use the same oil in gas and diesel engines, but sometimes don't they call for the same kind of oil? Is there really "diesel" oil and "gas" oil? I know I've seen a few times an oil that says it is for diesel engines, but is it really diesel-specific? I've never seen in any of my trucks and tractors owners manuals that it calls for "diesel" engine oil. It usually calls for 15w 40 OR 10w30 depending on ambient temperatures and maybe with a few specific standards to be met. gas engines usually call for 10w30 or newer engines often call for 5w20. I've never seen a gas engine call for 15w 40, so i guess you could say that is a diesel engine oil, but only because of the thicker viscosity and not because of any other special additives right? I use the rotella t6 pictured above in my atvs because after much research I found that is recommended by a lot of professionals. Actually I feel safe using the rotella t6 in just about any engine, but I only run it in my more important/expensive/heavily used engines because it's more expensive. I've found the rotella t6 is also highly recommended by some professionals in diesel trucks especially in the winter. But I know even professionals fall for some of these oil myths. You can go to a lot of sites online or talk to a lot of professionals and hear a lot of contradictory things.

@Big Enos,

That is no longer true with Synthetic oils. PAO synthetics in the beginning would cause seals to shrink and cause an oil leak but that has long since been overcome with adding the correct amounts of group 5 synthetic oil. PAO is a group 4 synthetic.

I use Redline which is group 5 synthetic oil in my Ram Pentastar engine and it runs great on it.

Your information about synthetic oils is very old and no longer valid.

My 2007 V8 Ram says in the manual to change every 3,000 miles. I usually change between 3-5,000 miles. It states to use 5W-20 and I always use 5W30 or 10W30 depending on the time of year and add a half quart of Lucas. Always running strong and I'm at 130,000 miles.

I'd be really careful with #7. Many manufacturers (my Jeep Wrangler is a good example) specifically state in the warranty booklette that a specific oil meeting specific material standards is required and failure to use that oil and follow the guidelines in the manual may result in loss of warranty.

It would be VERY difficult and costly to fight the manufacturer in court when their own printed materials specifically tell you what is and is not allowed pertaining to engine maintenance.

If your owners manual says "under no circumstances should oil change intervals ever exceed 8,000 miles" like mine does, and you purposefully go 15,000...good luck convincing a judge that the auto maker should fix your ride.

@ Red: Your 2007 Ram owner's manual states that you use 5w20 because your truck has the Hemi V8. You don't specify that it has the Hemi, but the only Ram engine that year that requires the 5w20 is the Hemi. It is required for proper MDS (cylinder deactivation) operation.

I know a guy who had a Ram for ten years and 100,000 miles and never changed the oil. Truck still ran fine.

@ beebe

To know if an oil is gas or diesel check the back of the bottle. There will be a starburst on the back side with some letters in it. S tells you it has met the criteria for spark ignition engines (gas). The S will be followed by a second letter that signifies the grade of the oil. The higher the letter in alphebetical order the higher the quality generaly speaking. It will normally say in your owners manual what letter grade the engine requires as well as viscosity. Oil for a diesel will have a C for compression ignition followed by letters or numbers depending on its grade. The diesel grades are a little harder to decifier especialy the European diesel engines. You will get numbers for MB (Mercedes) VW (volkwagen/Audi) followed by a bunch of numbers that pertain to scpecific standards each manufacter requires for their engines. Many oils will have an S and a C rating of varying grades regardless of the viscosity.

@Jordan L - the letter after S or C in the oil designation is not a quality grade. It's a spec standard, designated by the American Petroleum Institute (API). Every time the standards are updated, the letter is advanced, so you know you are getting the newest oil specification, not necessarily the "best". For example, CJ oil is formulated to a newer standard than CI, but a given brand of CJ-spec oil can still be "worse" than a "good" brand of CI-spec oil.

I use Rotella T6 in my small engines because it still has the phosphorus and zinc additives. Supposedly, those are harmful to catalytic converters. Shell says "Rotella T6 5W-40 meets API CJ-4 and SM specifications, thus can be used in both Diesel and Gasoline engines. However, when used in a gasoline engine, it can potentially shorten the life of the catalytic converter." I think that would only be in the case of excessive oil consumption -- a lot of oil has to be getting to the cat to affect it. Based on everything I have read, T6 is the ultimate bargain in premium motor oil, available at any Wal Mart. Especially for motorcycle use where the same oil is circulating through the engine, clutch, and transmission.

I have used Mobil One in my Avalon, which is now starting to burn oil at the rate of one quart every 5,000 miles. While that is very disappointing compared to when it was new, I guess some wear can be expected after 300,000 miles.

@beebe - I've always been told that one has to be careful with oils used in dirt bikes, ATV's or street bikes that have an integrated transmission and engine. The oil has to be formulated to survive the shearing forces of the transmission, meet the lubrication needs of the engine but not be so "slippery" as to adversely affect the friction plates in the clutch (assuming a wet clutch).

Looks like PUTC is asleep at the wheel once again.

GM is putting the Corvette 8L90 automatic into their 1500's. It will be standard with the 6.2.

This was posted on TTAC (a car site) and appears to be on multiple other sites as well.

Mark must of forgot to check his emails this morning unless GM decided PUTC is a waste of time.

Many of the new vehicles use synthetic only. Our 2013 CRV uses a 0w15. I put Mobile 1 (5w30) in my Isuzu and one of my lawn mowers, a Honda Hydrostat self propelled. It seems the oil stays cleaner for a longer period of time. The Honda mower has had the oil in it for a while now and it looks like I just changed it and it has not used any oil.

I use the rotella t6 in my honda atvs because the owners manuals say to use an oil that meets JASO-MA specs. I've been told if it has JASO-MA printed on the label it is safe for wet-clutches. Rotella t6 and t5 are the only two oils I can buy at wal-mart that have that printed on the label. I can go to the dealer and buy honda oil, but it costs twice as much and I don't believe it is any better. It says "diesel engine oil" on the label of the T6, but it also has the SM designation on both. I did not know what the C and S stood for, so that is good to know, but I guess I was right that diesel engine oils aren't always necessarily just for diesel engines. If they were, they wouldn't put the SM designation on these oils

@beebe - Recreational dealerships (ATV, bikes, boats etc.) are worse than car dealerships for mark up. One has to be careful as to what one buys. I get all my bearings, seals, bushings etc. from an industrial bearing supplier. They are 1/4 the cost of a RV dealer.

@Ram Big Horn 1500, do you know if Amsoil signature series 100% synthetic is class 4 or 5? I always thought it was a PAO but now thinking it may be a class 5 Ester after reading what you wrote about redline?... Ive always used Amsoil in my vehicles that I bought new after breaking in for 30,000 or so KM. never had any of them leak at seals.

My understanding is Amsoil would be a group 4 oil with some group 5 added to it

Nothing wrong with Amsoil except for their crappy marketing of the bogus 4 ball wear test that has nothing to do with how an oil will perform in an engine.

It is hard to find a substandard oil today.

I have been using synthetic oils in all my vehicles now for some time, at least 20 years, and in any of them I have not had any oil use issues, be it 4 or 2 wheels, and the one thing not pointed out in it self is the benefit you get a really cold temps with the syn oil, as when the oil is very cold, say below 10% F, regular oils can get very thick, while syn oils are not subject to the really cold temps, and that is where most damages are done to engines! The temp issue in air cooled engines is even more sensitive with high temps, and for that reason alone I use syn oils in all my air-cooled bikes and cars.

Valvoline High Mileage oil is all I use in my engines and transmissions, I just retired my 2000 Silverado with 271,000 miles on the original engine and transmission, no rebuilds! I only changed the engine oil when the OLM told me to which usually was between 5,000-7,000 and the transmission fluid I only chenged twice in it's long life.

The Honda mower has had the oil in it for a while now and it looks like I just changed it and it has not used any oil.

@Jeff S

It is surely due to the fact that most people's lawn mowers probably run fewer that 200 hours per year--in the north a lot less. Where Lou lives a mower probably rusts out before it gets 200 hours on the motor.

Where I live it's an easy 200 hrs per yr because I use it on all of our rentals and the house where we live between visits from the gardeners.

Two hundred hours on a typical auto engine is nothing.

I use to change my motor oil every 3,000 miles till 92,000 miles. I have been told my engine oil should be changed every 6,000 miles because i use mobil one. So now i go 6,000 miles.

My new Dodge Hellcat is going to take 0W-40 synthetic oil that was developed for SRT by Pennzoil.

Pennzoil has a new synthetic made from natural gas.

I've always changed my oil every 3,000 miles, and I have no plans to change now. My car has nearly 200,000 on it and doesn't burn a drop. This is the cheapest insurance I know of for any vehicle.

I like this one - never use synthetic oil in a new engine as it will never break in.

a new synthetic made from natural gas.

@Hemi

Natural gas is cheaper today than it's been in many years. It's also pretty stable in storage compared to crude oil. The article correctly points out that crude is quite variable in quality and composition. Natural gas is probably much less variable.

And it's really cheap hydrocarbon.

I change my oil every 1,000 miles, which is about once a month. Its cheap insurance and would never think of going 3,000 miles without changing it.

Just out of curiosity, can somebody with ecoboost check what manufacturer request for oil change is in the maintenance book please.
I promise, I wan't start flame war.

I have a pulse injection on demand oil change system.
Processor controlled monitored with a PDI to constantly replace used oil with new oil. I have a 50 gallon fresh oil tank and 50 gallon used oil tank. No oil is used for more than 4 hours or less depending on how aggressively I tune the PDI.

Had a 98 maxima changed the oil every 15/20k miles with Mobil 1 synthetic and sold the car at 200k miles didn't burn a drop of oil.

Also my friend who is a mechanic said he remembers when synthetic first came out he use to change his piston and ring in his dirt bike every season , first season on synthetic he said it looked brand new could not believe it

@loubc
We go through a lot of bearings. I've learned that john deere actually uses cheap chinese bearings. So does case IH and New holland. I can go to the dealership and pay 100 dollars for a bearing, or buy the exact same bearing from the same manufacturer for 25 bucks a mile away at a bearing supply store, or I can pay 50 bucks at the bearing supply for a superior brand. I've heard that "honda" oil is actually just pennzoil or some other brand that has basically just been rebadged.

@beebe - it does pay to "pay attention" ;)

@PapaJim - My mower runs 1 1/2 hours per week for 4 months maybe 5 tops. My snow-blower gets more use ;)

I use Tech2000 10W-30 oil from Wal-Mart or Sam's Club, usually the cheapest I can find.

Use it in all my cars. One is 25 years old. Another 21 years old. My truck is a 1997 and our newest is a 2012.

No problems. Change oil every 3000 miles or once a year for those cars that never reach 3000 miles in a year.

I understand most people are brand loyal with motor oil.
How do you know the brand you use is the best?
Can you taste it? Are the ingredents listed ?
99% of the motor oil is made from polyethylene (paraffin wax, the same stuff your milk carton is made from)
In your city or area you live in the country almost all brands of motor oil are mixed together under the same roof, the same refinery-plant where they get base oils shipped in then mixed together.
It doesn't matter what brand you buy cause its made from the same base oil.
Not many people can understand the difference between a synthetic and conventional motor oil.
Why do you spend $15/qt for a synthetic when you don't know what it is?
You're going to pour something in your engine that you don't know what it is cause someone else told you its the best?

What about the oil filter?
A while back SAE tested oil filters and the Purolator Pure One came out on top ( its listed on the box the oil filter is in that its the #1 rated filter)
The other brands that did well are the Mobil 1 and the AC Delco.
What good is it using a $15/quart top of the line synthetic when you're not using the best rated oil filter to go with it?
What's the purpose of a "bypass valve" in an oil filter? What does it do? Why is it there? Is a bypass valve made from plastic, rubber, metal, or cardboard? Where is that bypass valve located in an oil filter? Is the bypass valve the same as an anti-drainback valve? Whats the difference?
Do you know?
Have you ever thought about the engineering design of the engine of where the oil filter is located on the engine or if your oil filter is plumbed into the pressure side or drain side of the engine?
No, I didn't think so.

I get my oil changed at Wal Mart less expensive than buying the oil and filter and doing it myself plus if the engine blows up cause they used the wrong oil or didn't fill it right Wal Mart will pay for a new engine.

Amsoil diesel extreme here every 15000 miles. My 2003 Duramax still running strong at 247000 miles, it doesn't use or leak anything. I swear by Amsoil.

@papa jim--That maybe true about the lawn mowers, but the Molbil 1 does seem to stay a little cleaner and it takes less than a quart of oil so the cost is minimum. The Honda calls for a 10w30 oil which most lawn equipment uses a straight 30. I use 10w30 Castrol in my S-10 and it usually gets changed before 3k because I only use it for hauling stuff and for the park and ride unless it snows. For traveling any distance I use the Isuzu or the CRV because they are newer and more comfortable. The most important thing is to change your oil and filter on a regular basis. The Postal Service and some government vehicles have used motor oil made out of soy beans on an experimental basis which is similar to the synthetics in that it lasts longer (doesn't break down as fast as regular motor oil).

patpa jim--Years ago I worked for an independent oil man in Houston who at the time had a 75 Cadillac Sedan Deville that had over 200k miles and looked and ran like new. Most of the mileage was highway mileage which is much easier on a vehicle than short distance stop and go traffic. This man was also fanatical about maintaining his vehicles with the regular oil changes and tuneups and maintaining the exterior and interior which were always spotless (showroom new). This man told me he once had a 56 Cadillac Fleetwood that he bought off his boss when he was younger and used it in his business--mostly highway miles. This Fleetwood had over 500k miles on it with a valve job at about 200k miles but the car itself was in excellent condition. His wife drove it for years as well till she decided she wanted a new midsize car. Most of today's vehicles are more than capable of going 200k miles and beyond and if the bodies are not exposed to salt and chemicals used to melt snow or the salt air of the sea they will last a long time. Maintenance is the key to keeping a vehicle a long time and in the long run it is less expensive. As the old commercial said "You can pay me now or pay me later."

Change your oil based upon time:
Mobil warrants M1-Extended Performance to 2 years/15k miles. Regular Mobil1 for 1 year/10k miles, and their lower grade for 6 months (5,000 miles on conventional, and 7,500 miles on synthetic-which ever occurs first)
ALWAYS fill your oil filter before installation. Otherwise if you install a dry oil filter, you run without oil for about 2 minutes. (don't go to 'qwicky places' that install oil filters empty/dry.
With a new engine, start with the thinnest oil first, and work your way up as it ages.
0w-20 for the first 75,000 miles 0w-25 for the next 75,000 miles, 0w-30 for the next 75,000, 0w-35 for the next, then 0w-40.
Within reason, use the least amount of oil in the crankcase, so the oil warms up quickly. 95%+ of engine wear is 'cold start', when the oil is too thick, and the clearances too large.

http://www.bobistheoilguy.com/motor-oil-101/

@DeverMike/Paul/Tom Lemon/Greg Baird/TRX4Tom/Dave/Hemi V8/Tom Terrific/sandman 4x4/lautenslager/zveria/Bob/US Truck Driver/Glenn/Jason/Hemi Rampage/smartest truck guy/Maxx/SuperDuty37/Ken/Ron/johnny doe/jim/ALL1/Frank/Idahoe Joe/The Guy/AD/Casey/papa jim/Young Guy/BeeBe/Steve/Chris/The truck guy/Alex/Mr Chow/Yessir/All Americans/Scott/Buy American or say Bye to America/Ram Big Horn 1500/Hemi Monster/Tom Wilkinson at Chevy/mark49/Tom#3/Truck Crazy or whoever you want to call yourself.

Quit the crap, really.

It's getting long in the tooth.

You want to debate, but it has to be on your terms.

Learn to debate with good information, then we might be able to have a decent debate.

Opinions are good, but if they are only your view to support the UAW, then how good are they. Look at what you guys have done to Detroit.

Terror tactics (union tactics) don't work on me.

If PUTC wants the UAW or whatever to control this site I suppose it's their decision.

It's not kids like I've been told by PUTC.

Change intervals also depend on type of driving, dirt roads driven frequently, or everyday?

Around town stop and go, with shut it off and restart quite a bit?

They still say in some operators manuals that lots of freeway/higher speed driving should have you changing oil sooner, but that's something that was started before over drives were everywhere, and now most trans slow the rpm way down. Driving 3000 miles at 70-75 isn't quite so hard on them now, cakewalk.

15$ a quart for synthetic? I don't know where you go, I buy 5 quarts for 26$, that covers Mobil 1, and Castrol, and Quaker State 5w-20. Maybe you are thinking of Redline and Royal Rip-off Purple? Even then it doesn't cost 15 a quart, if you know where to go.

Maybe older diesels took 15-40, present day Ecodiesel takes 5w-30, the same as my 2006 Chevy 5.3 took. Wonder what year they made it take 5w-20? Probably same year they copied Dodges MDS? And for the folks that want to say it has so much extra maintenance, (where?) 10k interval with 8.2 quarts.

^lol, always fill your filter, or you run without oil for 2 minutes!, lol, Goerge! Filling the filter is good when possible, however not all applications let you. Some are upside down, or angled. Maybe no oil for a few seconds, but two minutes? I have heard it all! I wonder how those vehicles that I could not fill oil filter ever made that many miles?

You can start at 0w-20, I will start at manufacturers recommended grade, like stated earlier, 5w-20 is recommended in a 5.7 Hemi for the purpose of MDS.

@Turbo Yoda

The owners manual recommended oil change interval for the 3.7L, 5.0L, and Ecoboost are to follow the Intelligent Oil Life Monitor (IOLM), but never exceed 10,000 miles between changes. The IOLM will sense how your truck is being used and will shorten the interval according to that. This takes out the guessing game of whether your truck falls under the "severe duty" oil change interval that is stated in most manufacturers manuals.

Basically how it works is that it starts out at 10,000 miles which is for a non severe duty interval. The ECM will lower that amount depending on how the truck is used. If you high rev it for long periods of time, use your truck tow tow a lot, get your engine too hot for long periods of time, or take too many short trips then the IOLM will reduce that interval to 7,500 or even 5,000 miles. I notice when I tow a lot, my oil life monitor will drop quicker then when I am not. The manual also states to change to a 5,000 mile interval if the IOLM is not working.

@Turbo Yoda

I forgot to mention that I send my oil to get it analyzed by Blackstone Labs. The furthest I have every gone is 7,500 miles and they said my oil was still fine. They said I could go a little longer, but I wouldn't want to for my own preferences.

@TRX-4 Tom
Oil filters range from small, that take roughly 1/4 quart, 8oz to prime, normal mid-sized ones take 16oz, and the large PureOne PL30001 takes 3/4 quart.
So if you calculate how much displacement per crankshaft revolution, you can find how much time it takes to complete the oil circuit.
Worse if you immediately start the engine with cold/thick oil, and the oil pump needs to relieve excess pressure, so your time can increase-that is the worst case 2 minute situation.
The oil light will go off shortly, but that just measures oil pressure coming out of the pump.
Your engine survives, if you idle immediately after restarting, and you had residual high pressure additives in your old oil which keep metal-metal contact from occurring.
So it behooves you to prime every oil filter [the best you can-even if it is only half filled], regardless of the orientation. Just get it one, and spin it down and you don't lose oil/make a mess.

Most diesels take 40 weight oil, some allow for 30 weight for winter.
There is little difference between 0w-20 & 5w-20. Take the 0w-20 for winter & 5w-20 for summer.