5 quart jugs, huh??? Gotta love those Just a few months ago, Autozone was having the "DIY oil change" deal, where if you bought the 5q jug of Superflo(~$5), you got any Deutch filter free! Considering that filters for my previous car ('91 Legend) were $5+, I was actually getting the oil free! BTW, is there any real reason why the conventional Mobil oil is so cheap, at least comparing to Castrol, Pennzioil, etc???
...could be sold for under a buck a quart, and the companies seem to rotate in who is doing it. I catch 'em when they're cheap. Uhhhhh, big jugs or not!
I purchased a 2000 Chevy Suburban with 30k miles on the Vortec 5.3L. It has burned approx 1qt in 3000 miles. Service Mgr at dealership says lets keep an eye on it. Oil change tech says "that's nothing, you ought to see some of the Northstars that come in here". Should I be worried? Warranty runs out in 2000 miles.
Owner's manual I am sure says that as much as 1 quart in 1000 miles is acceptable. At least you have it documented while udner warranty should it get significantly worse but until it gets to 1 quar in 750 miles I doubt GM will do anything.
I would call GM/Chevy and get a case # from them. That way there is no question. That is assuming the dealer will do nothing about it- which is almost certain.
never used 1 quarter of a qt let alone a qt. Is a qt acceptable? not for me it wouldn't be. There is a reason for this loss. either it is mechanical such as blowby past the rings,valvestem seals leaking,head gasket leaking,valve covers or oil pan leaking or the other reason is burn off due to a poor grade oil.
I have found many people use a very poor grade oil and will not hold up thus disappating either past the rings/blowby and such or by accumilating as sludge in a hot spot on the motor.
no matter what, there is a reason for the usage and if I was to spend that kind of money for a brand new car/truck, it dang well better not use a drop of oil. period. There is No excuse that a manufacture can give me that will justify oil usage of any nature.
My suggestion to you is bring in a good grade oil in for your next oil change and see if your oil consuption drops. This would be the first step in determining if its the quality of the oil or something else.
Guess I misread. Somehow I was seeing 1 qt.every 1K. If you are using conventional oil its really not that abnormal in my opinion. Depending on the type of driving you do, especially with the SJ variety(higher volatility) and high speed driving it could be almost normal. That said, It's higher than I would be happy with. I had a '69 Camaro that used 1 quart every 1500-2000 milse from new. at 100K later it was still using the same amount. The key is does it get worse. If you switch to a better oil as Bob said and it says the same you just have loose rings-its also possible to have a broken ring.
Isn't it by definition that an engine has to use some oil but most people measure/gauge this by saying that I didn't have to add any so it doesn't use any. My definition is if the dipstick (measured at a consistent time, say morning before starting for the first time) drops it has used some oil. Now this also changes with the season, winter will produce a slightly different reading in the morning then summer and a long high speed trip will burn off water and perhaps fuel that has accumulated in the oil which may lower the reading the next time. Depends on how exact you want to be in terms of saying it uses oil. Sure over 3000 miles you may see absolutely nothing, give it 7,500 miles and I guarantee there will be some usage.
Now, in my camry, at 143,000 I use about 28 ounces in the 7,500 miles between changes (and this includes a very slight seepage on a few seals) and this has been consistent for the past 3 years. Prior to that slighly less oil.
My new Buick uses about 2 ounces every 1000 miles but it is consistent whereas my Mitsubishi twin turbo, in a year and 5000 miles same oil, may drop only 2-4 ounces.
I concur, the key is whether the usage is consistent and not increasing. Some cars use 1 quart every 3000 and it never increases as the engine ages. Lower tolerances I guess???
You make some very good points that I could not have put into words myself. I agree with your basic definition of 'if the dipstick drops, it has used some oil.'
Our 98 Trooper has been a quart low (according to dipstick) every 2000-2500 miles. This hasn't changed in the 56k miles we've owned the truck (bought used at 7k). Am I worried about this? Not at all. It's common on this engine, and it's not getting any worse.
I get tired of hearing people make very precise claims with very imprecise measurements to back it up. It's like the people who say, 'my car gets 20 miles per gallon. I know because I usually get around 300 miles before it gets between 1/4 and "E" and then I fill up and it's an 18-gallon tank.' Sorry, but those actions don't give you an accurate MPG figure!
In addition to the dipstick reading, I track how much oil I add during the change interval and how much is drained at time of change (I know you can't get all of the old oil out).
I must admit I don't measure how much oil I drain out (I do with tranny fluid) but I do keep track of how much I add. How else can you tell if something has changed?
Guess we have too much time on our hands. Need a mistress, well, maybe the cars replace the mistress, probably less expensive in the long run as well.
when i say mine hasn't used a drop, obviously i was refferening to the fact i have not once had to add even an ounce to mine(no i don't have time to measure exact amounts). my last oil change btw was with 11,287 miles on the oil and before draining, the oil was still sitting on the full mark which is where i measure mine. if it is below this line then i would notice that as well especailly if it was a qt low let alone 1/2qt. maybe i'm just one of the lucky ones, go figure. bob
Very nice. As I did note though, I have to use Explorer for me to bring up as my Netscape is older 4.7 and I refuse to upgrade.
Look forward to more now that you have the technology down. Maybe you should go into a new line, on line education, using the videos, power point presentations for all participants, new sideline.
OK, so maybe I just asked the wrong question, but I was trying to be cute and get myself a coupon for STP like you did by asking (what I thought was) the same question about the STP Oil Extender. This is the response I received.
"Unfortunately, the STP 6000 Mile Oil Extender is no longer available. Although a great number of consumers enjoyed it as you did, the sales volume was not substantial enough to warrant our continuing to market this product."
Anybody who claims their engine doesn't use a drop of oil either has no concept of how internal combustion engines operate or has a seized engine. ALL engines burn oil, some more, some less.
don't really think this says a lot. Looks canned, note the reference to SH and SJ oils...
Thank you for contacting us about STP Oil Treatment. We appreciate your interest in our product.
STP oil additives are fully compatible with today's high performance motor oils and do not contain any corrosive chemicals. Some of the additives contained in STP Oil Treatment are identical to the additives used in today's highest quality API SH or SJ multi-grade motor oils, but in higher concentrations. STP also contains viscosity index improvers and dispersent chemicals that enhance the performance of all motor oils. The effectiveness and compatibility of our product with today's oils has been thoroughly tested both at independent laboratories and by STP Research & Development. In every comparative study, these tests have shown that the STP Oil Treatment Products reduce wear and extend engine life.
STP Oil and Air Filters currently are produced by Champion Laboratories. If you have questions or comments about these products, please contact Champion Laboratories at (800) 882-0890. I hope this information is helpful.
I hope this information is helpful. Once again, thank you for contacting us.
Non of my 4 (including current) vehicles have NEVER had any oil ADDED and SHOWED NO decline in the DIP STICK READING no matter what milage i have on the oil.(as I pointed out before, i don't have the time to measure and weigh the oil evertime i do an oil change to see what exact grams are consumed in an engine.)
I'm not going to banter with you about oil usage as i am quite aware of how an engine lubrication system works and how the lubrication priciples apply in and to the engine. I will also tell you that if you are saying that an engine has to use a 1/2 to a full quart of oil to provide this lubrication then you have an engine using oil or has a leak.
Now that is something! My letter did not declare that the STP OIL EXTENDER product was gone forever, but it did say that I might have a hard time finding the product. I got the idea that they were about to produce it again with an accurate label that stated the presence of Molybdenum disulfide. All things considered, I must surmise that the product is a goner. I found a bottle of it, and redeemed my coupon. Now here is something I noted along the way, looking for the coupon product: At Walmart I could not find it, but noted the presence of the blue bottle STP product-- the classic STP thick petroleum. Along side it, in a very similar bottle was a house brand thick petroleum product for about half the price. I will guess it is STP under another name. This form of STP is not known to me to contain Molybdenum disulfide.
posted: Non of my 4 (including current) vehicles have NEVER had any oil ADDED and SHOWED NO decline in the DIP STICK READING no matter what milage i have on the oil.(as I pointed out before, i don't have the time to measure and weigh the oil evertime i do an oil change to see what exact grams are consumed in an engine.)
I agree - my last 4 japanese cars have neither leaked or burned any oil. My previous GM cars all leaked - pan and valve covers, and my VW did that and burned it too.
the stuff that costs 79 cents a bottle on two high mileage cars. Seems to slow down oil burning. I'm still a bit leary about using anything like that on low-mileage cars although I might think twice if the new son of SL oil regresses in wear inhibition. My assumption is that STP probably hasn't changed a great deal in the last twenty years but that it does have a place if you need more wear protection.
I use the generic STP also, here's a good hint.. That stuff is so thick I hate to pour it into the motor even if the motor is warm. I have a 5 qt jug of oil that I had bought some time ago, I add the oil first to that jug, then I add the STP into that oil and shake it up. The STP mixes right in and then I pour it into the motor,,no globs of thick stuff that way.. I won't use 5w/30 at all, only use 10w/30 during warranty and shortly after, start swapping out the 10w/40 or 15w/40 after about 50k miles and start adding some STP (maybe a half bottle) after 100k. 10w/30 has merit during cold winter starts, but heavier oil really helps during hot summers,,,and "mature" engines. see Y'all Rando
I'm glad you could find some. I've looked around but haven't had any luck. I've emailed the local Schaeffer's distributor to see how I could buy some #132, but no response so far.
they have it listed in their online store, but you have to call 1-800-325-3367 to order. It's $5.50 pt. Minimum 4 Pints + UPS Shipping. I'm thinking of ordering some as well.
I have Mobil Drive Clean (10W-30) and Tri-Sync (10W-30). Can I pour them together into my car? Is there a ratio issue I need to be aware of? Thank you for your input
But which oils are generally thought to have diminished wear protection? Is it the SJ (or earlier), the SL, or the not-yet-released Sx oils?
I'm willing to spring for some pricey moly from Schaeffer's, but before I do that I want to be sure it makes sense to add their Moly 132 to an SL-rated 5W30 or 10W30 such as Citgo Supergard or Chevron Supreme.
I keep up with these threads, but unless I write up the consensus findings in a separate file, I invariably forget the main points.
of the engines i have seen where people dump in different oils.
I can see now that I need to explain what happens with oil mixing.
It is not advisable to mix brands of oils. each oil company has their mix of additives and one can clash with the other.
(in layman terms here is a scenario) Additives have an infinity to metal attraction. the defomants,antioxidants,detergents,antiwear and all the other additives when mixed can cause a problem because too much of one thing can cause another additive not to work.
lets take the higher levels of mo in redline for example. because the mo is so high, the antioxidant additive has a much harder time protecting the oil from acids, therefore the detergents have to kick in sooner and clean up the acids the antioxidants couldn't keep out. That then causes the tbn levels to drop faster and once down to a certain point the oil will be overcome with the acids and the base oil will start to breakdown sooner. So to mix oils especially when you have no idea what you are mixing, would not be beneficial and in cases i have seen, sludge will form. Of course you can get away with it for a while and in some cases forever. If mixing oils is what you want, it should be the same brand of oil to avoid additive clashes since most companies maintain the same basic chemistry in each of their oils.
Now understand that redline is a good oil, and works well. I only used that as an example on how one can effect the other and that this example is only hypothetical and not nesccarely representative of how redlines oil may actually be.
There is a guy named tim in arkansas that will sell it by 1 or 21 +shp. the ep is 5.00 per bottle from him or 3.00 per qt of oil. just call him 800-737-1747 as he is not that good on emails but will get to them since most of his business has been direct connect and this seems to be his first experience in getting people to use the emails for ordering info.
I do mix synthetic and conventional oils now. Why? 2 reasons. On most Oils I can't get a straight answer about the percentage of syn in a blend, or what type of syn they are using, and I would like a higher percentage than what Quaker State told me their blends were 20 -- 25%. Valvoline after much pressure said their Maxlife was 15% syn with a severely hydrocracked base oil and special additives. I want more synthetic, but not too much since I have an older car.
I do follow the following guidelines. I try to stick to the same weight of oil as much as possible. Valvoline told me that mixing weights is uncertain, and not to do it. I always keep the oils in the same brand. So the only real mixing I do is an additional quart of syn to the desired oil. My latest was adding a quart of synthetic to an oil change with Maxlife. It seems to be working well.
Check back on post 1177 and 1183, we were all talking about this subject back there. I have no problem mixing oil wt, just depends on what my goal is, under warranty I use what the mfgr recommends, where I live 5w/30 is not required for ambient temps and I use 10w/30. After the vehicle gets to 50k I start swapping either (10w or 15w)/40 for 10w/30 about 2 out of 5 qts, during the heat of summer I will use 20w/50 instead of the (10w or 15w)/40. I have higher interest in engine protection over slightly higher gas mileage,,,the mfgrs have a MUCH higher interest in the slightly better fuel economy that thinner oil gives (CAFE standards are hard on them but don't care how long I keep a vehicle!),,,,and they know that the majority of people either lease vehicles or sell them before they really hit high mileage. I usually keep vehicles for a long time, which is why my interest leans towards better engine protection. I try to keep the different wts all with the same mfgr, but there have been a couple times where I was changing brands that I mixed mfgrs (I used Castrol GTX before and use Havoline now) I have only had 1 premature motor death and that was a Chevy 4.3 that only used 10w/30 until it died at 107k miles, all my others have gone to at least 190k miles using thicker oil before I sold them (all running fine when I sold them). Different strokes for different folks, but that's how I do it. See y'all Rando
Bob, I've mixed a few oils (synthetic & dino) in some of my small engines but in general I keep those occasions rare as I used to give out the same warning that you just did. There's always a chance that one company's additive will refuse to "play nice" with another's. >;^)
But how much of a risk does mixing pose? After all, aren't all API certified oils supposed to be compatible? Every time you change your oil you leave behind 10-20% of the previous oil so each time you switch, you are mixing oils ... to some degree.
However, even if the resulting mixture doesn't do actual DAMAGE to a motor, the combination of additives may cause one or the other to perform at less than optimum levels ... which means the resulting mix isn't working as well as it should ... and isn't that the point? When one mixes, they want the beneficial attributes of a better oil without using a full concentration of it, right?
All in all, I don't mix much anymore ... but there are a few applications where I want some of the flow and heat-resistance properties of a synthetic ... and the anti-wear and additive package of a diesel oil. And, with these machines (some of which I don't own) I don't bother buying Red Line. It's too expensive.
What Schaeffers product are you referencing from Tim in Arkansas, is it the Moly EP Oil Additive? I have used Schaeffers Supreme 7000 15w40 oil in my diesels in the past. I have also used in some of my gas engines, although I am not using it at this time. Schaeffers is manufactured here in St. Louis and has a strong following with fleet and diesel owners. By the way, the Moly EP can be ordered from the Schaeffers site for $5.50 per pint with a four pint minimum.
Yeah, I remember the discussion. That's why I tried to say I try to avoid it. It's a personal decision. However in one car the mechanic recommends a 5W-40 oil. The Brand I used in it doesn't carry 40 weight, and the 50 makes a substantial difference on my gas mileage. Last Fall when I changed the filter I added 5W-30 to thin it. they weren't quick changing the filter, so it took 2 quarts to refill. So by the math I should have a 5W-40 oil.
But since they are configred by the manufacturer for specific weights my preference is to stick with the real weight I want. For this reason I'm switching brands on the next oil change.
You said you are changing brands? I don't remember seeing any 5w/40, what brand are you talking about (not being smart, just curious)? I am using Havoline now, I will probably change to Chevron when I use up all the oil out in the garage. I check gas mileage every tank on every vehicle I have ever owned,,going to thicker oil never hurt the mileage enough to complain about, I have always used heavier oil during summer (also running the A/C) and the mileage only changed maybe about 5-10% and the A/C could have done that by itself.. How much do you think using heavier oil hurt your mileage....In my case, it has never been significant, I just care more about keeping the engine than getting maybe 1-2 more mpg... I have never lived up north, so I probably do not have a good perspective on thin oil,,,,,but I have lived in the south...(Florida to North Carolina..) and the summer heat is a killer down here..that's why I go with thicker oil. see ya Rando
Hi, the host told me to post here instead of where I did, I guess so nobody will see it. Ah, it don,t matter. I just wondered if after an oil and filter change if anybody circulates the oil before starting the car. Read my other post about circulating the oil. I tried to cut and paste, like I was told, but it didn,t seem to work. OH, well anyway. It was just a cold rainy day, thought I would post, didn,t intend to irritate the host. My computor skills leave alot to be desired. thanks
Actually this is a very popular topic. And the deal is that when you post-that topic goes to the top so lots of people read it. You probably get some extra wear by just starting up the car and waiting for the pressure to build up but who knows how much. Now if you have a Chevy the odds are unless its a 4 cyl that the filter is vertical in which case you probably fill it before putting it on. If you just ran the car and the oil is hot and you drain it- when you start it there is already a reasonable oil film on it. You also are not putting a load on the engine. The reason it can't be that bad is that I once had a ford 2.3 L and I used filters (horizontal mount) without the anti-drain back vale for years. It rattled seriously thousands of times when it started up. That same vehicle (when my son owned it) had a 90% plugged oil pump screed and rattled without the light coming on for usually a minute for about 6 months. That vehicle with 145K is still on the road. I rest my case.
where the barrier lube properties of the oil was working when it was running dry during start up. Just like it was designed to do. So with a good barrier lube, you'll find that start up wear isn't as bad as some would imagine.
I just wanted to post some other results I just did while I had time. I now know that from my little personal tests that mobils tri synth seems to have some differences over the years. the oldest I had was an sj rated, when run, it would plate up in a reasonable time simular but not quite as fast as amsoils. the newer sl grade trisynth, would also plate up but after a longer period of time. Then of course mobils new supersyn oil, I couldn't get it to plate at all no matter how hard I tried.
of course this isn't scientific but it does show me that every one seems to have less and less antiwear barrier lube property the newer it was.
STP 6000 mile oil extender.. first observation showed to be dark and thin fluid like, not thick as the older standard stp additive. The older stp additive plated up in a reasonable time as expected. In comparision, the newer 6k stp didn't fair as well. After the new stp plated, I then proceeded to put some extreme pressure to see if it could be sheared and without too much force i was able to lock it up. The point of this is, that if moly is present it is near impossible to shear it once plated up. so if moly was in this product i'd think it was just barely tainted and that's all. The other indicator of zddp is the caution on the bottle states don't get into eyes also is commonly used in high does of zinc. This statement is not normally indicated in moly additives.
Valvoline has a 5W-40 synthetic that I will be changing to this weekend. Since it has a large amount of hydrocracked that will work to my advantage for my older car.
what do u guys think of marvel mystery oil i usually put a half bottle in at every oil change i use 1540 oil for the remainder is this a good combo for an engine my van has 100k
jc1973:I personally would not mix the MMO with my oil because I really do not know what it is really going to do for me. I think a quality engine oil has everything it needs to do the job. In the old days I used to put it in also.
If you are going to use it, my suggestion is to put it into the gas where it can provide some extra lubrication to the injectors ant the rings. I occasionally use it there. I believe my milage goes up slightly when I use it. That sorta makes sense.
Comments
BTW, is there any real reason why the conventional Mobil oil is so cheap, at least comparing to Castrol, Pennzioil, etc???
We'd better move along. I hear "host" keyboards beginning to stampede!
I have found many people use a very poor grade oil and will not hold up thus disappating either past the rings/blowby and such or by accumilating as sludge in a hot spot on the motor.
no matter what, there is a reason for the usage and if I was to spend that kind of money for a brand new car/truck, it dang well better not use a drop of oil. period. There is No excuse that a manufacture can give me that will justify oil usage of any nature.
My suggestion to you is bring in a good grade oil in for your next oil change and see if your oil consuption drops. This would be the first step in determining if its the quality of the oil or something else.
Now, in my camry, at 143,000 I use about 28 ounces in the 7,500 miles between changes (and this includes a very slight seepage on a few seals) and this has been consistent for the past 3 years. Prior to that slighly less oil.
My new Buick uses about 2 ounces every 1000 miles but it is consistent whereas my Mitsubishi twin turbo, in a year and 5000 miles same oil, may drop only 2-4 ounces.
I concur, the key is whether the usage is consistent and not increasing. Some cars use 1 quart every 3000 and it never increases as the engine ages. Lower tolerances I guess???
Our 98 Trooper has been a quart low (according to dipstick) every 2000-2500 miles. This hasn't changed in the 56k miles we've owned the truck (bought used at 7k). Am I worried about this? Not at all. It's common on this engine, and it's not getting any worse.
I get tired of hearing people make very precise claims with very imprecise measurements to back it up. It's like the people who say, 'my car gets 20 miles per gallon. I know because I usually get around 300 miles before it gets between 1/4 and "E" and then I fill up and it's an 18-gallon tank.' Sorry, but those actions don't give you an accurate MPG figure!
In addition to the dipstick reading, I track how much oil I add during the change interval and how much is drained at time of change (I know you can't get all of the old oil out).
Guess we have too much time on our hands. Need a mistress, well, maybe the cars replace the mistress, probably less expensive in the long run as well.
bob
Look forward to more now that you have the technology down. Maybe you should go into a new line, on line education, using the videos, power point presentations for all participants, new sideline.
"Unfortunately, the STP 6000 Mile Oil Extender is no longer available. Although a great number of consumers enjoyed it as you did, the sales volume was not substantial enough to warrant our continuing to market this product."
Am I missing something?
Thank you for contacting us about STP Oil Treatment. We appreciate your interest in our product.
STP oil additives are fully compatible with today's high performance motor oils and do not contain any corrosive chemicals. Some of the additives contained in STP Oil Treatment are identical to the additives used in today's highest quality API SH or SJ multi-grade motor oils, but in higher concentrations. STP also contains viscosity index improvers and dispersent chemicals that enhance the performance of all motor oils. The effectiveness and compatibility of our product with today's oils has been thoroughly tested both at independent laboratories and by STP Research & Development. In every comparative study, these tests have shown that the STP Oil Treatment Products reduce wear and extend engine life.
STP Oil and Air Filters currently are produced by Champion Laboratories. If you have questions or comments about these products, please contact Champion Laboratories at (800) 882-0890. I hope this information is helpful.
I hope this information is helpful. Once again, thank you for contacting us.
Sincerely,
David N. Mills
Product Specialist
I'm not going to banter with you about oil usage as i am quite aware of how an engine lubrication system works and how the lubrication priciples apply in and to the engine. I will also tell you that if you are saying that an engine has to use a 1/2 to a full quart of oil to provide this lubrication then you have an engine using oil or has a leak.
Now here is something I noted along the way, looking for the coupon product: At Walmart I could not find it, but noted the presence of the blue bottle STP product-- the classic STP thick petroleum. Along side it, in a very similar bottle was a house brand thick petroleum product for about half the price. I will guess it is STP under another name. This form of STP is not known to me to contain Molybdenum disulfide.
Non of my 4 (including current) vehicles have NEVER had any oil ADDED and SHOWED NO decline in the DIP STICK READING no matter what milage i have on the oil.(as I pointed out before, i don't have the time to measure and weigh the oil evertime i do an oil change to see what exact grams are consumed in an engine.)
I agree - my last 4 japanese cars have neither leaked or burned any oil. My previous GM cars all leaked - pan and valve covers, and my VW did that and burned it too.
That stuff is so thick I hate to pour it into the motor even if the motor is warm.
I have a 5 qt jug of oil that I had bought some time ago, I add the oil first to that jug, then I add the STP into that oil and shake it up. The STP mixes right in and then I pour it into the motor,,no globs of thick stuff that way..
I won't use 5w/30 at all, only use 10w/30 during warranty and shortly after, start swapping out the 10w/40 or 15w/40 after about 50k miles and start adding some STP (maybe a half bottle) after 100k.
10w/30 has merit during cold winter starts, but heavier oil really helps during hot summers,,,and "mature" engines.
see Y'all
Rando
they have it listed in their online store, but you have to call 1-800-325-3367 to order. It's $5.50 pt. Minimum 4 Pints + UPS Shipping. I'm thinking of ordering some as well.
Chris
I'm willing to spring for some pricey moly from Schaeffer's, but before I do that I want to be sure it makes sense to add their Moly 132 to an SL-rated 5W30 or 10W30 such as Citgo Supergard or Chevron Supreme.
I keep up with these threads, but unless I write up the consensus findings in a separate file, I invariably forget the main points.
I can see now that I need to explain what happens with oil mixing.
It is not advisable to mix brands of oils. each oil company has their mix of additives and one can clash with the other.
(in layman terms here is a scenario)
Additives have an infinity to metal attraction. the defomants,antioxidants,detergents,antiwear and all the other additives when mixed can cause a problem because too much of one thing can cause another additive not to work.
lets take the higher levels of mo in redline for example. because the mo is so high, the antioxidant additive has a much harder time protecting the oil from acids, therefore the detergents have to kick in sooner and clean up the acids the antioxidants couldn't keep out. That then causes the tbn levels to drop faster and once down to a certain point the oil will be overcome with the acids and the base oil will start to breakdown sooner. So to mix oils especially when you have no idea what you are mixing, would not be beneficial and in cases i have seen, sludge will form. Of course you can get away with it for a while and in some cases forever. If mixing oils is what you want, it should be the same brand of oil to avoid additive clashes since most companies maintain the same basic chemistry in each of their oils.
Now understand that redline is a good oil, and works well. I only used that as an example on how one can effect the other and that this example is only hypothetical and not nesccarely representative of how redlines oil may actually be.
I do follow the following guidelines. I try to stick to the same weight of oil as much as possible. Valvoline told me that mixing weights is uncertain, and not to do it. I always keep the oils in the same brand. So the only real mixing I do is an additional quart of syn to the desired oil. My latest was adding a quart of synthetic to an oil change with Maxlife. It seems to be working well.
I have no problem mixing oil wt, just depends on what my goal is, under warranty I use what the mfgr recommends, where I live 5w/30 is not required for ambient temps and I use 10w/30.
After the vehicle gets to 50k I start swapping either (10w or 15w)/40 for 10w/30 about 2 out of 5 qts, during the heat of summer I will use 20w/50 instead of the (10w or 15w)/40.
I have higher interest in engine protection over slightly higher gas mileage,,,the mfgrs have a MUCH higher interest in the slightly better fuel economy that thinner oil gives (CAFE standards are hard on them but don't care how long I keep a vehicle!),,,,and they know that the majority of people either lease vehicles or sell them before they really hit high mileage.
I usually keep vehicles for a long time, which is why my interest leans towards better engine protection. I try to keep the different wts all with the same mfgr, but there have been a couple times where I was changing brands that I mixed mfgrs (I used Castrol GTX before and use Havoline now)
I have only had 1 premature motor death and that was a Chevy 4.3 that only used 10w/30 until it died at 107k miles, all my others have gone to at least 190k miles using thicker oil before I sold them (all running fine when I sold them).
Different strokes for different folks, but that's how I do it.
See y'all
Rando
But how much of a risk does mixing pose? After all, aren't all API certified oils supposed to be compatible? Every time you change your oil you leave behind 10-20% of the previous oil so each time you switch, you are mixing oils ... to some degree.
However, even if the resulting mixture doesn't do actual DAMAGE to a motor, the combination of additives may cause one or the other to perform at less than optimum levels ... which means the resulting mix isn't working as well as it should ... and isn't that the point? When one mixes, they want the beneficial attributes of a better oil without using a full concentration of it, right?
All in all, I don't mix much anymore ... but there are a few applications where I want some of the flow and heat-resistance properties of a synthetic ... and the anti-wear and additive package of a diesel oil. And, with these machines (some of which I don't own) I don't bother buying Red Line. It's too expensive.
--- Bror Jace
Schaeffers is manufactured here in St. Louis and has a strong following with fleet and diesel owners.
By the way, the Moly EP can be ordered from the Schaeffers site for $5.50 per pint with a four pint minimum.
But since they are configred by the manufacturer for specific weights my preference is to stick with the real weight I want. For this reason I'm switching brands on the next oil change.
How much do you think using heavier oil hurt your mileage....In my case, it has never been significant, I just care more about keeping the engine than getting maybe 1-2 more mpg...
I have never lived up north, so I probably do not have a good perspective on thin oil,,,,,but I have lived in the south...(Florida to North Carolina..) and the summer heat is a killer down here..that's why I go with thicker oil.
see ya
Rando
The reason it can't be that bad is that I once had a ford 2.3 L and I used filters (horizontal mount) without the anti-drain back vale for years. It rattled seriously thousands of times when it started up. That same vehicle (when my son owned it) had a 90% plugged oil pump screed and rattled without the light coming on for usually a minute for about 6 months. That vehicle with 145K is still on the road. I rest my case.
Later,
Al
I just wanted to post some other results I just did while I had time. I now know that from my little personal tests that mobils tri synth seems to have some differences over the years. the oldest I had was an sj rated, when run, it would plate up in a reasonable time simular but not quite as fast as amsoils. the newer sl grade trisynth, would also plate up but after a longer period of time. Then of course mobils new supersyn oil, I couldn't get it to plate at all no matter how hard I tried.
of course this isn't scientific but it does show me that every one seems to have less and less antiwear barrier lube property the newer it was.
STP 6000 mile oil extender.. first observation showed to be dark and thin fluid like, not thick as the older standard stp additive. The older stp additive plated up in a reasonable time as expected. In comparision, the newer 6k stp didn't fair as well. After the new stp plated, I then proceeded to put some extreme pressure to see if it could be sheared and without too much force i was able to lock it up. The point of this is, that if moly is present it is near impossible to shear it once plated up. so if moly was in this product i'd think it was just barely tainted and that's all. The other indicator of zddp is the caution on the bottle states don't get into eyes also is commonly used in high does of zinc. This statement is not normally indicated in moly additives.
If you are going to use it, my suggestion is to put it into the gas where it can provide some extra lubrication to the injectors ant the rings. I occasionally use it there. I believe my milage goes up slightly when I use it. That sorta makes sense.
Al