How often Do You Change Oil

[blakkwidow]

I change mine when my caddi says so... I think it's at 7500. I'm using Mobil 1 fully synthetic though...

[stsjoe]

272,000 and I go by the OLM, Oil 10-30 usually Penzoil (Dino) No leaks and runs great, Engine has never been touched

Joe

[kcd1184]

I use the OLM and have gone from changing at 30% to the change oil soon warning. Had 7000 miles in 2 months this time. Used to use 10/30 Valvoline High Milage but the last 2 times I switched to Advanced Auto High Milage. No observable differences. The Eldo is running great except for a few hard shifts every now and then. The new Michelens are just GREAT!!!!! I added probably 3 quarts in that period.

Kent

[beetlejuice]

I use Shell Rotella not shure about the wt.

In my 92 Deville I change about every 3k miles.

I also got an 89 Seville and the Indicator comes on at about 3k miles.

Neither of them get driven very much.

[JohnnyG]

The build up of moisture and incompletely burned fuel is typical of short trip driving and can lead to the formation of acids in the engine oil. In fact, continuous stop and go driving can be relatively severe because the engine oil may not heat up sufficiently to allow these contaminants to boil off. All Mobil 1 technology, including Mobil 1 and Mobil 1 Extended Performance, offers better protection against the build up of contaminants than standard petroleum-based oils because it is formulated using carefully selected performance additives rather than simply based upon a standard additive package. Many of these additives are specifically designed to cope with the build-up of contaminants and to help neutralize harmful acids. Mobil 1 is recommended for the longest drain intervals recommended by the respective OEMs (original equipment manufacturers), while Mobil 1 Extended Performance is guaranteed to protect critical engine parts for up to 15,000 miles.

This is so much marketing crap! I can't believe you fell for it! First, they are telling you something that you already know, that short trip driving builds up moisture quickly, and it doesn't get burned off. DO YOU DRIVE YOUR CAR ON SHORT TRIPS ALL OF THE TIME? Then they tell you that ALL of there oils are designed to handle this problem....ie (all Mobil1 technology). Then they tell you something that you want to hear..."it is formulated using carefully selected...." what? like all the other oil manufacturers throw a dart at a board and whatever "packeage" it hits is the one they use that day? Not likely! Then they tell you something that you SHOULD know..."Many of these additives are specifically designed..", OF COURSE THEY ARE! Why else would you use them? Then they go on to reinforce the OEM recommendations, which I like the best because GM recommends that you use the OLM! Wonderful, after telling you how great this stuff is, they tell you to follow the OLM anyway!!! Marketing, gotta love it!

[JasonA]

I'm using Shell Rotella in 10W-30 weight right now in the STS. Because I only drive about 6-7k miles per year, I just change the oil every 5k. The OLM would let me go to 10k easy, but you're also not supposed to go longer than once per year. So every 5k is an easy reminder in my situation.

[Cadillac Jim]

The build up of moisture and incompletely burned fuel is typical of short trip driving and can lead to the formation of acids in the engine oil. In fact, continuous stop and go driving can be relatively severe because the engine oil may not heat up sufficiently to allow these contaminants to boil off. All Mobil 1 technology, including Mobil 1 and Mobil 1 Extended Performance, offers better protection against the build up of contaminants than standard petroleum-based oils because it is formulated using carefully selected performance additives rather than simply based upon a standard additive package. Many of these additives are specifically designed to cope with the build-up of contaminants and to help neutralize harmful acids. Mobil 1 is recommended for the longest drain intervals recommended by the respective OEMs (original equipment manufacturers), while Mobil 1 Extended Performance is guaranteed to protect critical engine parts for up to 15,000 miles.

This is so much marketing crap! I can't believe you fell for it! First, they are telling you something that you already know, that short trip driving builds up moisture quickly, and it doesn't get burned off. DO YOU DRIVE YOUR CAR ON SHORT TRIPS ALL OF THE TIME? Then they tell you that ALL of there oils are designed to handle this problem....ie (all Mobil1 technology). Then they tell you something that you want to hear..."it is formulated using carefully selected...." what? like all the other oil manufacturers throw a dart at a board and whatever "packeage" it hits is the one they use that day? Not likely! Then they tell you something that you SHOULD know..."Many of these additives are specifically designed..", OF COURSE THEY ARE! Why else would you use them? Then they go on to reinforce the OEM recommendations, which I like the best because GM recommends that you use the OLM! Wonderful, after telling you how great this stuff is, they tell you to follow the OLM anyway!!! Marketing, gotta love it!

Where is the post are you speaking of? I coudln't find it in this thread...

[JasonA]

Where is the post are you speaking of? I coudln't find it in this thread...

It was in the first link you posted.

It's funny that Mobil has now come out with Mobil 1 EP...Mobil 1 is specified for a NUMBER of engines that have OLMs that go way beyond the claimed 15,000 mile guarantee of the EP oils. Such as many BMWs, etc. Their EP product is really redundant -- as is their Mobil 1 HM. They claim that if you use Mobil 1, you don't need the HM, but if you run other oils, you could benefit from HM. Okay...

It's simply loading up their product line to get shelf space. Nobody's going to stock 800 quarts of Mobil 1, so they stock 200 quarts of Mobil 1, 200 quarts of Mobil 1 EP, 200 quarts of Mobil 1 HM, etc... Retailers still keep a reasonable amount of each type of product in stock and Mobil keeps the shelf space.

[JohnnyG]

JasonA is correct, the post is from a link that was in this thread.

I must add a few little things here, especially since we haven't had a good "oil war" lately. Mobil1 has quietly "cheapend" their products lately to do just EXACTLY what Jason pointed out. There is a lot of history involved, but it boils down to this: At one time, Mobil1 was a TRUE synthetic oil....there are a few from MY point of view, but Mobil1 was a true PAO (poly Olefin something or other). Then Castrol started marketing THEIR version of a synthetic oil, which in reality was not a TRUE synthetic, but a lubricant made from HIGHLY modified base stocks (look up hydrotreating). Mobil1 took them to court for marketing an inferior product as a true synthetic, a judge ruled in Castrol's favor, and ever since then, the word "synthetic" took on a new meaning......legally.

Mobil Oil Co. is not stupid. They immediately realized that they could make a bunch of money doing the same thing that Castrol did, and slowly switched their formulations away from PAO to GROUP III oils, with a little 100 solvent neutral as an additive carrier. They did not lower the price however. And in keeping with current marketing logic, started selling HM, 4X4, 5000 mile, etc. etc. just like everybody else. Main goal??? $$$.

In essence, any SM oil is now a synthetic...oil manufacturers can't meet this tough new standard any other way. I'm not talking PAO here, but HIGHLY MODIFIED BASE STOCKS. So to buy anything marketed as a synthetic is a complete waste of money, since all SM oils will meet the testing requirements, and meet or exceed the manufacturers warranty requirements.

I use Chevron Supreme 10W-30 in my 1999 Northstar. Though it only has 89,000 miles on it, it's as clean as a whistle inside, uses JUST THE RIGHT amount of oil (like a quart/3000 or so) and gets between 25 and 27 mpg on a trip @72 mph. Oh yeah, I almost forgot, I spike it with about 1-2 ounces of Valvoline Synpower Oil Treatment for the extra little bit of ZDP, at every oil change. I figure that additive is pretty close to the GM oil additive metioned earlier in this thread.

[abad95]

I believe in changing the oil a little before time.Usually 20% or so.That's around 3000 miles or so.

I used to be into trying all the oils and stuff.Waste of money.

I use Supertech Oil from Walmart.

The Caddy loves fresh oil and being maintained properly.Take care of maintananance on time before you get to repairs if you could.

That's the main thing.

I have 195000 miles half highway- half street driving.

I do wait wait until it warms up before I put my foot in it.Especially in really cold weather.

Don't be fooled by expensive oil.

I do believe in good gas though...(Shell or Sunoco)

Florin

[OynxSTS]

I believe in changing the oil a little before time.Usually 20% or so.That's around 3000 miles or so.

I used to be into trying all the oils and stuff.Waste of money.

I use Supertech Oil from Walmart.

The Caddy loves fresh oil and being maintained properly.Take care of maintananance on time before you get to repairs if you could.

That's the main thing.

I have 195000 miles half highway- half street driving.

I do wait wait until it warms up before I put my foot in it.Especially in really cold weather.

Don't be fooled by expensive oil.

I do believe in good gas though...(Shell or Sunoco)

Florin

Yep to all of that, I'm even cheaper though I driver her down to 10%...

cheap Wallyworld Oil works great...

and I run cheap gas with no issues either...

I drive all of my cars like I just stole them and I've never had an oil issue...

Oil problems seem to be more a function of engine design and packaging (Toyota sludge) then oil brand, or cost.

[stsjoe]

I think you can sum the whole thread up with "Whatever gives you peace of mind"

[Cadillac Jim]

Jason -- People don't necessarily believe everything to be found in every link that they might post. Scanning a link for the worst marketing BS you can find and quoting it as something people believe is... uh... reaching.

All -- There is more to oil than knowing that what you are doing won't hurt engine life. My main reason to use Mobil 1 5W-30 is that there is a subtile but definite improvement in "snap" or throttle response over what I see with even the best 10W-30 dino oil, which to me translates to slightly better performance as well as the much-advertised slight improvement in gas mileage.

One of the other benefits of synthetic oil is tolerating higher temperatures well. That isn't a factor in most normal or even heavy use of Northstars, but it just might be a factor in cases where you have very low oil pressure or blinking oil lights. Note that when you overheat a Northstar past a certain point, the PCM zeros out the OLI. If you are running synthetic, you can see that message with a little more assurance that it's not an immediate emergency to change the oil right then.

Regarding the change of formulation of Mobil 1 -- there was a Q&A section on the Mobil 1 web site where the question was put directly and the answer was not clearly given, citing the obvious fact that the formulation of their oil was proprietary. That probably means that everything we associate with "real" synthetic oil is less true about Mobil 1 now.

What can we say about Amsoil? Their synthetic oil was once "real" synthetic. Is that still true?

[OynxSTS]

Jason -- People don't necessarily believe everything to be found in every link that they might post. Scanning a link for the worst marketing BS you can find and quoting it as something people believe is... uh... reaching.

What can we say about Amsoil? Their synthetic oil was once "real" synthetic. Is that still true?

What can I say about Amsoil... Not much..

I find Amsoil to use the worst marketing BS of the bunch... Historically they refused to submit their oil to any independent testing... With the promise of "trust us".

Yes Amsoil used to be "all" synthetic... now they have several lines of oils ranging from, 100%, to some synthetic and now they have a "cheap" line that is sotra synthetic... they also have some oils that they have finally had SAE tested and validated...

Coming from the guy (me) who uses whatever is cheapest at walmart, I wouldn't use Amsoil even if it were given to me... not because I think it is a bad oil... I just can't tolerate their pyramid marketing techniques...

[JohnnyG]

Don't blame Jason for quoting that link, that was me. Oh, and by the way, I didn't "scan the worst link", it was just the first one I clicked on. I did it to point out that there can be many reasons for marketers to write something, usually it is done in the intrest of increasing sales (that's their job). It's sort of an "eye of the beholder" thing. If you read those lines and think that those statement make that product the best in the world, all it proves is that the spin doctors did their job well.

As to Amsoil. It may still be a fine oil, but I don't care for their "pyramid" type marketing tactics either. They may still market a PAO, but you would be hard pressed to identify exactly which product it is. As to the testing by SAE, there can be MANY reasons for them not to do that. What if their oil was tested, but due to the high amount of ZDP or some other additive, it fails SM certification? Would sales go down or increase? The product might be actually better than anything else, but could not be sold as SM. This is only a smallpart of the whole story, don't read too much into it. The point here is that SAE or any testing is in place to ensure minimum standards of compatibility between manufacturers of two completely different product, in this case one is automobiles and the other motor oil.

Has anyone tried Royal Purple?

And by the way Jims_97, you do realize that you are comparing apples to oranges when you campare 5W-30 Mobil1 to "any other 10W-30". You should at least compare oils of the same ratings. Mobil1 10W-30 has historically been the thinnest synthetic out there, let alone their 5W-30.

[JasonA]

An apples-to-apples comparison, in the name of performance, might be Mobil 1 5W-30 vs. Havoline conventional 5W-30. From what I understand, the Havoline is about the thinnest conventional oil out there in the 5W-30 viscosity. I may use it next. I'm using the Shell Rotella due to the thick formulation and the high levels of anti-wear, but since the 2000+ Northstar engines don't need that same level of ZDDP-type additives, I may be wasting fuel economy and performance with the Shell.

[WarrenJ]

I think you can sum the whole thread up with "Whatever gives you peace of mind"

One word: AMEN

Regards,

Warren

[Cadillac Jim]

Don't blame Jason for quoting that link, that was me. Oh, and by the way, I didn't "scan the worst link", it was just the first one I clicked on.

I didn't even reat that stuff. In fact, when I saw it quoted, with the lead-in "... I can't believe you fell for it!" I didn't know where it came from, and I had no idea who JohnnyG was "talking" to. After clarification, I feel sure that he was talking to someone who doesn't exist.

Regarding Amsoil, I haven't tried to get any yet, but I do remember some test results I saw posted here some time ago that showed some variety of Amsoil as being the only other oil that matched Mobil 1. I would get it online, and I'm satisfied from the posts here that I would either end up getting the wrong flavor or paying too much for it. I think I'll stay with Mobil 1 for awhile, unless GM drops it or I see some test results that put it on a par with premium dino oil. In the meantime, I do notice that the price of Mobil 1 hasn't dropped at all.

I used Havoline many years ago but got away from it when I was driving a car with a high compression engine that got indigestion on the Texaco gas of that period and region. There's no question in my mind that there is no better dino oil than Havoline in its product line class. What about the premium oils of other mainline companies, such as Shell, etc.?

[clarkz71]

I used to use Mobil 1 because IT IS better than dino oil. After 29 years of being an

automotive technician I have seen plenty of examples of that fact.

Anyway, I change my oil at 3000 to 4000 miles. Since I can't seem to go more than that

I switched to Shell Rotella 10/30 as I couldn't justify using Mobil 1 with such short oil change intervels.

I still however use Mobil 1 V-twin 20/50 oil in my new Harley as it's an air cooled engine.

[JasonA]

I just put Mobil 1 5W-20 in our 2007 Chrysler Town & Country minivan a few weeks ago. I don't know if I really expected any difference in how it ran, but I didn't perceive any. I'll leave it in for a while. The MPG has increased markedly, but that also coincides with the end of our seemingly endless 90-100*F weather in North Carolina, so I'm sure that's the difference-maker.

Unfortunately, Chryslers don't have OLMs like the Cadillacs do. We put about 15,000 miles per year on our family vehicle, but since the owner's manual recommends something near a 5000-6000 mile oil change interval, I'm not comfortable extending beyond that, even with a "synthetic" oil. The powertrain also has a lifetime warranty, so I won't be changing my OCIs when the engine "goes out of warranty" because it never will. I suspect that I'm not seeing any benefit from the double-the-price Mobil 1 oil with 5000 mile OCIs in an engine/application that's as easy on oil as a minivan driven in North Carolina. No real cold starts, no REAL hot weather, enough highway driving, etc. I paid about $22 for the 5-quart jug of Mobil 1 at Wal-Mart, but all the others (including the "semi-synthetic" branded Motorcraft 5W-20) were in the $10-12 range. I don't think there's a real difference in "conventional" and "semi-synthetic" anymore because as JohnnyG pointed out, all API SM oils are at least partially synthetic now.

I guess I'll go back to the Motorcraft 5W-20 in the van. I'm thinking of a light 10W-30 or a 5W-30 for the STS next...just to see if I see any MPG/performance increase over the relatively thick Shell Rotella.

[Cadillac Jim]

Summing up what I see here:

• For maximum engine life, use any oil with the starburst symbol, in the viscosity range recommended by the owner's manual. That's 10W-30 in most Cadillacs. There are lots of good dino oils out there that meet that description that are available at very modest cost, particularly in gallon or other bulk sizes. Havoline is among the best.
• If you see very cold starts (0 F or colder weather, car not in heated garage or parked outside at work or on errands), follow the owner's manual; most often the recommendation there is to go to 5W-30. In the past few years some owner's manuals say to use synthetic or 0W-30 for cold starts much below 0 F.
• If you have very high temperatures (racing, CTS-V or Corvette high speed WOT driving, etc.) or wide temperature ranges (air cooled engines like many motorcycles), check with the manufacturer and the vehicle literature; synthetic is likely to be mentioned.
• Synthetic 10W-30, or 5W-30 dino or synthetic, may or may not provide a slight advantage in gas mileage or performance.

Off-topic, but important to the thread, we have

• Mobil 1 may not be all-synthetic anymore.
• Don't believe everything you read.
• Mobil 1 costs about twice as much as perfectly good starburst-grade oils that have all appropriate attributes to provide full engine life.
• A quart of ATF or high zinc break-in oil every once in awhile may be a good thing. The reason that this is so is because zinc additive levels in starburst-quality oils are limited over what we have seen in years past because of concerns related to life of the catalytic converter.

My own opinion (incoming...)

• In my previous car that had a Quad 4 HO engine, I could feel the difference between 5W-30 synthetic and 5W-30 dino oil instantly when I started the car after an oil change. More than once I have caught my dealer in an error with my 1997 ETC the same way -- start it up and immediately notice a loss of snap (throttle response off idle) and ask the service manager, and, indeed they put dino oil in it by mistake, and they take it back and put 5W-30 synthetic in it. The effect in the Northstar is far more subtle than with the much smaller Quad 4 HO engine, and short of numbers from a GTECH Pro or similar instrumentation on the same car on the same day, this can be taken with a grain of salt by those who perceive no such difference.
• Any improvement in fuel economy would accrue to less engine drag, which might be perceived as more engine snap, or throttle response off idle. Fuel economy, or "energy efficiency" is one of the most advertised advantages of synthetic oils. I believe that any advantage in fuel economy is seen in longer trips, not short trips from a cold start.
• The cost of oil for your car is tiny compared to the worth of the car to you. It's an individual decision on cost versus any perceived or actual advantage and the appropriate choice.

Now, if the Northstar had a crankshaft wiper...

[WarrenJ]

Now if the Northstar had a crankshaft wiper...

Now I understand there *IS* such a thing as a crankshaft wiper, but maybe you'll forgive me for thinking, after your post, I need to check my turn signal fluid.

Just the same, a fine post!

Regards,

Warren

[apache13]

I over-do my oil changes at around 2500 miles...My eldorado has 130K and I really don't want to have the engine R&R'd anytime soon...might be overdoing it but it never hurts to replace oil and filter at 2500...

Anthony

[BodybyFisher]

I over-do my oil changes at around 2500 miles...My eldorado has 130K and I really don't want to have the engine R&R'd anytime soon...might be overdoing it but it never hurts to replace oil and filter at 2500...

Anthony

This is bigtime overkill and a waste of natural resources. I couldn't defend your action if my life depended on it. Do some reseach on the OIL LIFE MONITOR

[MAC]

I over-do my oil changes at around 2500 miles...My eldorado has 130K and I really don't want to have the engine R&R'd anytime soon...might be overdoing it but it never hurts to replace oil and filter at 2500...

Anthony

My silver Eldo is approaching 228,000 miles and it still runs like new and I change oil according to the Oil Life Monitor. In other words, I have saved $1000 (at $25 per oil change) compared to changing every 2,500 miles. The savings can be used to make repairs.