Motor Oil



  • quadrunner500quadrunner500 Member Posts: 2,721
    Not bad karma to use Castrol Syntec, an excellent synthetic oil. But you should instead choose 5W-30 Syntec. It is not thinner, the synthetic polymer base stock for both is 5W oil. The difference is the additive blend, or viscosity thickeners. Remember a multi-viscosity like 5W-50 is never as "thick" as a 50W single grade except at extreme temperatures. The 5W-30 oils have high temperature protection (vaporization point) that is just as good or better than 10W-40. Where the synthetics really exceed is cold start pump-ability. Many say this is where the most engine wear occurs. So the ideal oil is the thinnest one that maintains shear strength to prevent metal to metal contact. This type of oil flows quickly to lubricate parts that start dry. Note that the 5W-50 does not have the API "starburst," symbol, meaning it is not a fuel saving oil, whereas the 5W-30 is.
  • cdeancdean Member Posts: 1,110
    Use what your owner manual says!! If you don't like 5W-30, look through the manual, sometimes they list other choices you can use in certain conditions ie, 10W-30, 30W...

    the wider the range of the synthetic, the more polymers there are to break down. 10W-50 has more polymers 10W30. I read some student research internet site about testing on multiweights, and it said that the wider range oils performed worse than lower range oils, long term.
  • shoozshooz Member Posts: 27
    Ok, ok, fellows, I see the evil of my ways and I'm ready to repent. Syntec 5W-30 it will be! The point about the API 'starburst' symbol is well taken...
  • KatmanduKatmandu Member Posts: 24
    First off,I think there is a lot of good information in all the posts. It's quite obvious that simple maintenance will increase the life of your vehicle. My personal experience is that the synthetics are more slippery (duh) than dead dino oils. My proof came when changing from organic to synthetic in a VW Golf. It idled 200rpm faster after the synthetic oil change. But, however, the cost of these oils is too great for me to continue every 3K miles. Therefore I choose one brand/one weight and stick to it for the life of the vehicle. All oil out of the ground is the same, different manufacturers add different additives. That's what makes a quality oil. Every car I've had has lasted well over 100K miles w/o an oil related engine problem. My latest guinea pig is a 1983 Subaru Wagon with over 200K miles on it and as ugly as it is, it runs perfect. It does burn about 1/4 quart between each oil change but I figure I can add $0.25 worth of oil. I have been using 10W30 quakerstate because it is cheap and seems to be of high quality. I'm sure most other brands are just as good. Maybe if I went to a 10W40 my oil burning would be reduced but I don't want to make the rings any more lazy than I'm sure they already are. I suppose if I owned a $25K car I'd do whatever I can to make the thing last near forever, but my $225 Subaru will be just fine for now..Geez, I just realized that in the last 2 years ive paid as much for oil changes as I did for the car...Pretty depressing!! =) Good luck.
  • RichRich Member Posts: 128
    No, I didn't mix the 20/50 and 10/30. What I've done is to purchase oil in volume. I've got a lot of SAE 30W left from the '92. I have a local dealer that is always sending something in the mail. (Win a new Expedition or the like.) It seems that until lately, the booby prize was an oil change for your Ford vehicle. After the second free oil change, the rules are now "Except Diesels". So, slowly but surely I'm using the old stock of 30W. When it's gone, I'll probably try some of the WalMart stuff. You can't go too far wrong with V Q or P oil.

    The only things that I've really noticed is that 12 quarts fills the crank case according to the stick and 30W seems to get "used" quicker than 10W30. The 30W is down a quart at about 5K miles and the 10W30 isn't. The 20W50 never goes down. But that may be because the dealer puts 14 quarts into the crank case, I don't know.
  • cdeancdean Member Posts: 1,110
    that's odd, my father's diesel burned a quart of oil between changes when he used multiweight but didn't use hardly any of that when he used straight 30. it reasons that multiweight would slip past the rings or burn off easier because its so much less viscous.
  • markbuckmarkbuck Member Posts: 1,021
    My old 7.3 was the same, 15W-40 quart every 2,500 to 3K. When I would run straight 30W, would not be measurable between changes. I fiqured when motor was cold, had blowby usage with the light weight, once warm, both oils were held by the tighter clearances.
  • ghtrapghtrap Member Posts: 26
    Some of you have quite a bit of knowledge about oils, so I'd like to ask your opinion.

    I have a new '98 Explorer with the SOHC 4.0 (4,000 mi), and a '92 Accord 2.2 ltr 4cyl (100,000 mi).

    I have always used 10W30 Valvoline, but noticed that both owner's manuals say to use 5W30. I switched the Accord over a couple of changes ago and have already changed the Explorer once to 5W30 Quaker State.

    My questions: 1) Is 5W30 the way to go, and is it as good as 10W30 in the heat of the summer?
    2) Should I have switched the Accord over to Quaker State after 100,000 miles with Valvoline?
    3) Is Quaker State as good as Valvoline? It seems to be priced slightly less.

    Note: I definatlely change oil and filter every 3,000 miles whether it's overkill or not. I figure as long as I change that often, any quality brand ought to be equal for long engine life.

  • lwflwf Member Posts: 223
    I know it's been said that free advice is worth exactly what you paid for it, but you asked and I'll express an opinion. I'd stick with the Valvoline or perhaps at least a half-dozen other name brands, but I wouldn't use Quaker State, even in my lawnmower. I'd also use the 5W30, but I doubt if you could find anyone who ever ruined an engine by using 10W30. In other words, I doubt if matters much.
  • cdeancdean Member Posts: 1,110
    my truck specifies 5W or 10W 30, but i never use 5W 30 because in the heat here in Texas, when you drain 10W-30 out of a hot (opereting temp) vehicle, it flows like water and has about the viscosity of water. I have a hard time trusting that, and 5W would be even worse. 5W-30 oil is really a 5W oil with additives to make it act like 30 weight. It really, though, never is 30W. Even you live in a moderate cool climate, then 5W should be OK. But temperatures in the 80's, 90's, 100's, are really in the upper allowable range for 5W.

    The truck manufacturers specify 5W-30 because its range of temperatures covers the entire US climate range, from Michigan to Texas. 10W-30 isn't rated to protect in the low temperatures that our Yankee friends get every year. So the manufacturer's cover their "warranty" loop holes by specifying an oil that "techincally" should work everywhere. they don't have to take into account that stretch of 4 days it was 105° in the shade, and your oil was boiling...
  • quadrunner500quadrunner500 Member Posts: 2,721
    I agree with that. In fact my operating manual, while it states you should use 5W-30, says it's okay to use 10W-30 if the outside temperature does not go below (not looking at the book here) about 20F or even 0. But remember, for the same viscosity, a synthetic has a higher shear strength, not just more slippery or viscous. It's the strength of the molecular bond that protects you from metal to metal contact. Slippery-ness can be controlled with friction modifiers like dialkyl dithiophosphate. Viscosity can be controlled with viscosity extenders (additives in the oil). But in my old '89 Ford 460 motorhome, I don't hesitate to put 15W-50 Mobil-1 synthetic in it, because it doesn't see the day to day start-up cycles of a passenger car, and it's likely the protection it needs is when towing hard highway miles when it's hot, like down there in southeast Texas. (Great engine by the way, and great state.)
  • tungletungle Member Posts: 56
    Hi akjbmw,
    I'm very ignorant about car. Could you please explain about "the rings did not seat"?

    To all, I am considering using full synthetic on my new truck. Would that cause any problems? Please advise.
  • quadrunner500quadrunner500 Member Posts: 2,721
    I put synthetic in my new truck at 1404 miles. I am still able to sleep at night. Synthetic fills are still how some BMW's, Corvettes and others are delivered from the factory. If they don't worry, why should you? If after 300,000 miles, the rings still have not seated, you can worry then.
  • tungletungle Member Posts: 56
    Hi quadrunner500,
    Thank you, and I'll use synth on my new truck.
    I would still like to know what it means "the rings get seated".
  • quadrunner500quadrunner500 Member Posts: 2,721
    The piston rings are made from thin, spring like hard metal. They are held in place inside grooves in the wall of the piston. They seal hot gases from escaping around the clearance between the piston and the cylinder wall, and into the crankcase. They also keep oil from escaping past and into the combustion chamber. The rings are made from hard steel alloy, whereas the cylinder liner is made from cast iron. The liner is honed with a stone so its surface is roughened, allowing it to hold a thin film of oil. The rings have high brinnel hardness, and no pockets for oil. What happens as the engine breaks-in is the two distinctly different surfaces burnish, or wear-in together as they mate. The harder ring keeps its shape but the softer liner sacrifices some metal, until the two smoothly wear together when all goes well. When the process is complete, the parts are mated together, and at that point, combustion chamber gases are sealed from reaching the crankcase.

    Some experts say synthetic oil is more slippery, and thus the parts do not wear-in, or shed metal. Others argue that synthetics are not actually more slippery, they just have a higher shear strength. Slippery additives, called friction modifiers, like dithiophosphate (I'm not a chemist) are the ingredient of STP (tm). In STP's old ads, the mechanic was unable to hold the small end of a screwdriver dipped in STP held between his fingers under its own weight. Not to say it doesn't's still around. But I think too much of it wrecks catalytic converters, so enough said.

    But the amount of friction modifier additives are not really different in synthetic oils. Other experts, including car manufacturers, supply synthetic oil as the factory fill.
  • DavyddDavydd Member Posts: 121
    So, is it necessary for rings to seat and will they with synthetic? The Chevy book doesn't go into detail on that. The only experience I have is from my previous Subaru car where the dealer emphatically recommended synthetic at about the 7,000 mile mark.

    I'll switch to synthetic before next winter since it is superior in cold weather and the coldest I experienced at my house was a -43 deg. F a couple of years ago!
  • ladyblueladyblue Member Posts: 326

    Thanks for all the really great info! Even though it wasn't I who asked the question, I still enjoyed learning the answer.
  • quadrunner500quadrunner500 Member Posts: 2,721
    Thank you. I heard your Ram came in the other day. I'm very happy for you. Keep us posted what you are doing!

    Hard to say if it is necessary for the rings to seat, but G.M. and others are shipping new engines with synthetics in the crankcase. Some engine technologies use microscopic thin hard coatings on the cylinder wall, or hard ceramic coatings, or ion implantation to make a real hard surface only molecules thick. Obviously, any scuffing at all on a hard thin coating wrecks it. So there is no seating of the rings on such a design. They have to fit right from the start. But most new engines still use cnc bored, cast iron liners that have been honed.
  • chevy2chevy2 Member Posts: 5
    oil changing procedure I am going to use on my new chevy pickup with a 5.3L engine.
    1) change oil at 1,000 miles
    2) replace filter with a Mobil 1 M1-206 and replace oil with Castrol's Syntec Blend 10W30
    3) Change oil every 3,000 miles and use Mobil 1 filter and Mobil 1 10W30 synthetic.
  • dave40dave40 Member Posts: 582
    Why Castrol ?
  • chevy2chevy2 Member Posts: 5
    I think castrol make good products and I use castrol's gtx 10w30 in wife's 4runner. Mobil does not make a blend and I wanted to "season" my engine a litte bit longer than quadrunner500 did. So I thought this would be a compromise before I went straight synthetic. I have read comments in "Truck Trend" magazine where users of synthetic oil have switched to conventional oil and began to have oil problems. "Truck Trend" recommends when you switch to synthetic do not go back. So, if I use castrol's syntec blend and notice oil leaks, I will switch to castrol gtx and hope for the best.
  • dave40dave40 Member Posts: 582
    Good Idea ! Worth considering.
  • tungletungle Member Posts: 56
    Thanks a lot for the great info.

    I would plan to have the first oil change at 700 mi with regular oil. Next oil change between 2K-3K will use full synthetic. Still no truck yet!
  • cdeancdean Member Posts: 1,110
    i see a lot of posts of people changing oil early in the new vehicle break in period. My take on it is---don't. Dealers and GM tech people have told me this, andwe did the same thing when breaking in large industrial rebuilt engines. your engine is going to wear a lot regardless of oil for the first 5000 miles. on large industrial engines, we ran the rebuilds on a dyno for the specified break in time, and then cut open the oil filters and inspected the paper. those filters were full of metal. But thats what they were supposed to be. all those engines went on to last their full life.

    if you want to change your oil early for peace of mind, i guess you can, but you are not going to harm it NOT changing your oil. your filter protects you from the damaging particles. These vehicles also, were not designed to break in like that. Most new trucks (that i'm aware of) are shipped with a special oil blend in the crankcase designed for the break in period. by draining that out before the period is over, you could be altering the desired break in patterns.

    Not going to debate this, just my opinion from info i've gathered from several sources.
  • tungletungle Member Posts: 56
    It makes a lot of sense if they do put some special blend for the break-in period. I'll check
    with my dealer on it. By the way, you know if they
    put that special blend in the '99 GMC Sierra?
  • tungletungle Member Posts: 56
    Just an after thought, then it would be good to change the oil filter some time before the first
    suggested oil change. True?
  • blightblight Member Posts: 22
    Here is a site that gets into some good detail on Chevy's oil minder system.

    That article is under the Jan/Feb magazine link.

    I am an engineer, and I have taken the class that they teach. I think that it is interesting that with this monitoring, GM figures the oil can potentially last quite a bit longer under decent conditions.

    I do have some information on a study that identifies how much longer an engine will last with a better oil filter. It is suprising how much it can affect the life of an engine. I will try to remember to look it up and pass it on. This and other things I learned in this class indicates that the cleanliness of the oil is the number one factor in shortening the life of an engine. I have also been looking into some filtering efficiencies of some different filters. It seems the filter manufacturers are finally starting to put out some more efficient filters.

    More later.
  • markbuckmarkbuck Member Posts: 1,021
    Great article and website, thanks. Will probably do a 1,000 then 3,000 mile oil change at first.

    I might then just follow the GM oil minder recommendations but would probably go no more than 7,500 miles between changes.
  • blightblight Member Posts: 22
    Here is some more info that I promised:

    This test data I believe was done by GM and SAE. Most oil filters are about 40 micron, and this data uses that as the comparison point. It identifies the additional life of the engine compared to the 40 micron filter.

    30 micron filter = 2 times
    15 micron filter = 3.3 times
    10 micron filter = 4.5 times
    5 micron filter = 8 times

    The best rated filter that I have found is the Purolator PureONE. Here is the web address for it.

    If you go to the PureONE FAQ link, they give more test data, and it is pretty much a 10 micron filter. If anyone finds others, I would like to know about them.

    From everything I have learned so far, dirty oil will wear out your engine a lot faster than any other factor. The first thing oil analysis programs at companies concentrate on is the oil cleanliness. Then if they can manage the additional testing for the additives, they do that too.
  • tungletungle Member Posts: 56
    I visited the website. It seems impressive. I called Pep Boy and they don't have a part for
    the new V8 4.8L and they don't even know if Purolator has made one for the new engines yet.
    Anybody who knows the part number for pureOne filter, please pass it on! Thanks.
  • markbuckmarkbuck Member Posts: 1,021
    Wrote purolater with that question, replyed quickly with the following:
    "That application uses a PL20123 oil filter in the PureONE product line."
  • markbuckmarkbuck Member Posts: 1,021
    Well, all you salesmen for chevy have a reason to be bummed.

    GM went online today with

    I just browsed all of the dealership lots in AZ for Silverados. Found a couple of 99's I liked. Will call them direct. The heck with this waiting and dealing with local guys.

    I suspect that 1/2 of all new vehicle salesmen at every dealership will be out a job in the next 5 years .......
  • markbuckmarkbuck Member Posts: 1,021
    Sorry about previous post, belongs in the GM topics.
  • scape2scape2 Member Posts: 4,123
    I have always used Pennzoil and Fram filters on my vehicles. A friend told me that NAPA oil and filters are the same thing? Any comments? is this true?
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