Switched to Mobil-1 and oil consumption dropped

[thu]

I posted this over at the other Caddy forum, but I'll post it here, too.

I used to have to add one quart of oil per 1000 miles when I used dinosaur oil.

At the last oil change, I switched to Mobil-1 synthetic and oil consumption has been cut at least by half. I drive 500-600 miles a week.

Why is this? I thought that oil consumption would at least be the same and expected higher. The only real difference in driving conditions is that warmer weather is here. I don't know how that affects oil usage.

I didn't change viscosity.

I have about 2500 to 3000 miles on the current oil. It's down a quart but haven't added any yet. The oil is still golden-honey in color.

Some of you may ask, 'why did you switch from dino to full syn?'.

- The price of regular motor oil has climbed to an avg of about $2/qt here in Wyoming. I've noticed that a 5 quart bottle of Mobil-1 5W-30 is still $20, or $4/qt. It used to be that regular oil was $1/qt and Mobil-1 was $5/qt. Now that the price differential between the two has diminished drastically and oil changes are now between 10,000 and 12,000 miles, I'm changing oil only once or twice a year. Thus, the $15 difference per oil change 'is in the noise'.

- I've always used Mobil-1 with spectacular results on my other Caddys. 235,000 on '85 Deville, 298,000 miles on '93 Deville - engine still going strong.

- In the winter, the engine cranks easier, presumably putting less strain on the battery, starter, etc. Yes, it gets cold enough here (about -30*F, sometimes -40*C) in the winter to make a difference that is easily noticed.

Anyways, just wondering why my oil consumption has dropped so much after switch to Mobil-1. Another good test will be to switch back to dino to see if the oil consumption goes back to prior levels, but that won't be for a good long while....

[Bruce Nunnally]

If your usage does not go up with Mobil 1, and the cost is competitive, that seems a good choice, especially in your climate.

I suspect you'd have to monitor the usage over a longer control period to be sure, but so far so good.

The CTS uses only Mobil 1, but I think that was because it did not include an oil cooler.

That's great that you are getting such good service out of your Cadillacs.

[thu]

Yes, good idea. I'll monitor oil usage over a longer period.

[mikeal1892]

Dear Oil User,

I have had much better luck running moblie one fully synthic oils in my northstar engines in my caddys... And I agree that it uses much much less. Runs cleaner as well. Lasts longer. As I put it a while back as they were doing my headgasket repair . The insides on the valve covers etc were so clean I could have used it as a dish for salad... Old timers on here like regaulr oil, and they will tell you so. The from the information I have gathered from the old timers the Guru said that these engines were desgined to run on regular oils and that they were to use oil. The synthic oil is considerable thicker if you ask me and I just wonder if that could be why it doesnt break down and brun that way.

With the newer version of the northstar Im seeing on the back of my Moblie one bottles that this product is being used by the factory in these newer Cadillacs... But I was using my premium oil before I found this wonderful site to maybe I'm just ignunt....lol I have ran Moblie One fully Synthic in every car I have ever had.. And the regular stuff a couple of times just to cheak it all out.. The oil debate is one of the most involved threads we have on this site. So you'll get all kinds of great points on this!!! Also you mine try running a little Lucas in that thing as well...

Every consumer has his point of view and thats what I truley enjoy the most is getting the feed back from this website. We all dont live in the smae place or have the same driving habbits keep in mind!!!

Its my job to try to sell people on Lucas products as they are orig from southern Indiana and with the new Lucas oil stadium coming to Indy.... Only Joking!

Michael-

This is on yer 2003 with only 43 k miles on it and its using oil ?

[WarrenJ]

I'm still just over 1200 miles/qt. or so on dino. Of course, baby is getting a little long in the tooth; I don't expect she might be a candidate for synthetic. More likely, I should look into one of those oils formulated for more "experienced" engines.

Your results seem contrary to what many of us here have been led to expect.

I hope you'll update us periodically. This could get interesting.

Obviously, at least the '85 was not a Northstar; was the '93 a 4.9?

And yes, switching back to dino after a period of time would make it very interesting.

Regards,

Warren

[Bill K]

My experiance w/Mobil 1 was that it cleaned the oil passages in a 4 cyl. Honda engine so that it didnt have lifter click when cold.

I wonder if the cleaning properties of the synthetic loosened your oil rings so that there isnt so much blow by.

Just a WAG (wild a$$ guess).

[BodybyFisher]

Thu, this actually surprises me. I would never think that your oil consumption would decrease with Mobil 1. Contrary to what Mike stated above, I believe that Mobil 1 is thinner than its stated viscosity. I decided that when I used it in my 4.9 that had the #1 main bearing knock. With Mobil 1, my 4.9 sounded terrible and the #1 bearing was substantially louder. I also used a lot of oil with Mobil 1 in my 4.9 whereas with standard oil i did not. Keep us up to date with your experience with Mobil 1. Do you know if your engine has an oil cooler? Mike

[MAC]

If you're willing to spend almost $7 a quart then go for it. I don't see how it will be more cost effective since it's more than double the cost of dino but, then again, money isn't everything if you like what you see. I might even be willing to give it a shot just to see what happens. It might be a waste of money but at least it will be a harmless experiment.

[JasonA]

I see the advantage to synthetic in cranking temperatures that far below zero. In North Carolina, we're subjected to the occasional 15*F morning, but that's about it. The 10W-30 conventional Havoline or Pennzoil does just fine in it. 152k miles and not a drop of syn. OCIs in the 5000-7000 mile range, according to the OLI.

Good to hear a different experience with synthetic though (reduced oil consumption). Keep us posted!

[KHE]

Synethetic oils do not allow extended drain intervals despite some of the companies marketing claims. The antiwear additive depletes at the same rate as conventional oil. I would recommend following the oil life monitor for the oil changes regardless of the oil used.

[Regis]

Synethetic oils do not allow extended drain intervals despite some of the companies marketing claims. The antiwear additive depletes at the same rate as conventional oil. I would recommend following the oil life monitor for the oil changes regardless of the oil used.

I remember reading that too Kevin. The way I understand synthetic oils is that they are designed to run at temperatures below and above the abilities of conventional oils (which are outside the range of normal operating temps anyways).....extreme conditions if you will. And I believe the synthetics are still supposed to be changed according to the OLM for the reasons Kevin mentioned.

My experiences with synthetics are neither pro nor con other than a small dent in the wallet. The times that I used synthetics I "expected" to see a difference. I found myself abnormally checking the oil more frequently ........"Wow, no consumption going on....great!". But when the newness had worn off and I was back to my usual driving habits and my usual rate of checking the oil level I noticed that the consumption was at least the same as conventional oil. So if it gives you peace of mind to use synthetic then by all means do. But if your car came from the factory with synthetic then it makes sense to keep using it for the life of the car.

[JasonA]

But if your car came from the factory with synthetic then it makes sense to keep using it for the life of the car.

Right -- because usually there is a specific engineering reason behind it. Such as the VVT mechanisms in the new Northstar. Or the lack of an oil cooler, especially on a manual transmission vehicle. Short of that, the use of synthetic probably will make no objective difference.

[keith_99_sts]

My '99 STS burns 1qt./1000 miles - and that's using Mobil 1. About 80K miles on the car now, but it's used oil since forever.

I wonder if dino oil will only go 500 miles on a qt.. That would have been good to know when I was trying to get this fixed under the now expired factory warranty.

1000 miles/qt. is, cough cough, "acceptable" to GM and outside of the warranty.

[BodybyFisher]

My '99 STS burns 1qt./1000 miles - and that's using Mobil 1. About 80K miles on the car now, but it's used oil since forever.

I wonder if dino oil will only go 500 miles on a qt.. That would have been good to know when I was trying to get this fixed under the now expired factory warranty.

1000 miles/qt. is, cough cough, "acceptable" to GM and outside of the warranty.

Keith that sounds excessive to me. I think one quart every 1500 is acceptible. Your car is using what mine used when I bought it. Have you tried this procedure?:

Get on open highway, start at 40 MPH, put tranny in second, 3/4 throttle to 60 then full throttle to 70, take foot off gas and let tranny pull the car down to 40, repeat 10 times... Have you tried that?

I do it once a month

[keith_99_sts]

... Have you tried this procedure?:

Get on open highway, start at 40 MPH, put tranny in second, 3/4 throttle to 60 then full throttle to 70, take foot off gas and let tranny pull the car down to 40, repeat 10 times... Have you tried that?

I do it once a month

Yes, I do that - and plenty of WOT at other times. I do recall the banished guru contributions here about sticking piston rings and carbon build up and this is supposed to keep the rings rotating and blow out the carbon. Sadly, if you aren't worse than 1000 miles/qt. the dealer doesn't consider it to be a warranty issue. The engine runs fine, no smoke out the back. This is the only car I've ever owned that requires me to travel with a case of oil in the trunk.

Using the built in oil life indicator the car goes about 6000 miles between changes. That's 5 new qt.'s added between oil changes. There is enough new oil going in that a full change at 6000 miles is probably a waste of time, except that the oil filter needs changing.

[JasonA]

This is the only car I've ever owned that requires me to travel with a case of oil in the trunk.

And to be fair, it's probably the only car you've ever owned in which the engine will look just as good inside at 200,000 miles as it did at 20,000 miles. We know one of the reasons for the aggressive hatch pattern on the cylinder walls is good oil retention. The negative is oil consumption sometimes beyond what was previously considered "normal" (mine does about a quart every 3000 miles). The positive is there is virtually no cylinder wear or top ridge as you would see on previous engines, even hundreds of thousands of miles down the road.

The harder I drive my car, the more oil it uses. Common sense. More RPM equals more oil used through valve guide seals and through the cylinder wall. As I've driven it much easier lately, my oil consumption has dropped drastically. I think the ring cleansing procedure is a valid one for cleaning stuck rings...but driving it like that all the time with good rings won't help the consumption...it'll be worse due to you driving it so hard.

[mikeal1892]

What about trying a motor wash before the next oil change ? Ive did they a few times.

[thu]

Your results seem contrary to what many of us here have been led to expect.

Yes, I posted here so I could get some feedback on what might be going on.

Obviously, at least the '85 was not a Northstar; was the '93 a 4.9?

Yes, the '93 Deville is a 4.9

Thu, this actually surprises me. I would never think that your oil consumption would decrease with Mobil 1.

Yah, it surprised me, too! However, I wonder if the much warmer weather we've been having has something to do with it. ?????

Contrary to what Mike stated above, I believe that Mobil 1 is thinner than its stated viscosity. I decided that when I used it in my 4.9 that had the #1 main bearing knock. With Mobil 1, my 4.9 sounded terrible and the #1 bearing was substantially louder. I also used a lot of oil with Mobil 1 in my 4.9 whereas with standard oil i did not. Keep us up to date with your experience with Mobil 1. Do you know if your engine has an oil cooler? Mike

My 4.9L has had Mobil-1 pretty much all but the first 17,000 miles of its life and it burns zero oil. My engine in the STS (N*) is 100% stock. So, other than the stock oil cooler, there is no aux oil cooler.

If you're willing to spend almost $7 a quart then go for it. I don't see how it will be more cost effective since it's more than double the cost of dino but, then again, money isn't everything if you like what you see. I might even be willing to give it a shot just to see what happens. It might be a waste of money but at least it will be a harmless experiment.

Actually, Mobil-1 is $4/qt and normal dino oil's cost has RISEN to an avg of almost $2/qt here (many brands). So, the cost differential is only $15 per oil change (that's $15 for every 10,000 miles or $30 per year for me).

Synethetic oils do not allow extended drain intervals despite some of the companies marketing claims. The antiwear additive depletes at the same rate as conventional oil. I would recommend following the oil life monitor for the oil changes regardless of the oil used.

Precisely. I'm following the Oil Life Indicator. Mileage between oil changes, as determined by the OLI, is about 10,000 miles.

I wonder if dino oil will only go 500 miles on a qt.. That would have been good to know when I was trying to get this fixed under the now expired factory warranty.

I expected the oil consumption to go up or at least stay the same. With dino oil, my STS was using 1qt / 1000 miles.

[BodybyFisher]

Thu, what dino oil were you using?

[thu]

Thu, what dino oil were you using?

It's whatever the Dealer was using. I don't know. It's not listed on the invoices.

[Scotty]

Oh OK, its probably Texaco Havolin but that's a guess

[thu]

Oh OK, its probably Texaco Havolin but that's a guess

Oh Yes, I think that's correct.

[Regis]

Interesting. I find it interesting because I go through about a quart of oil per 1000 miles too. Sometimes more and sometimes less depending on driving style. Now I don't carry a case of oil in my trunk like keith but rather 1-2 bottles. I know this "burning" of oil bothers some but the guru has said numerous times that it's perfectly normal (keith's situation sounds like it could be something else) and that the addition of fresh oil is beneficial. My former mechanic, Dave, said that it was normal. My current mechanic (used to drag race) was the head technician for several dealerships before reopening his own shop and he says the same thing. He's listed as a master technician with an impressive array of specialty certifications. Now with that kind of line up singing the same song who is the smart money on? The 1qt of oil per 1000 miles has this ol girl baring down on 225,000 miles. Is it a problem? I'll let you know after I hit the 250,000 mark.

[thu]

I would hazard a guess and say that if your oil consumption doesn't *change*, then there's nothing to worry about.