Reading a road test recently on a new muscle car the very first comment made in the article was the author discovered a can of oil in the trunk. Leading him to believe oil consumption was a problem on this brand new vehicle. During the test he made an issue of the fact he had to add two more quarts of oil during the test time.
A new car should need to have oil added? Of course it is a magazine test car so not exactly brand new, it had some miles on it.
Triggering a thought on my part and a bit of research I found that many manufacturers are indicating that 1000/qt of oil is perfectly normal. A number that I have found over the years is an indicator that the engine is pushing it's last miles as any car I have owned other than the very first ones I purchased as late model used cars from the era of post WWII and would be about 8 to 10 years old.
The 1947 Desoto I purchased from a Lincoln Mercury Dealer on sale for $17.00 consumed oil quite well and eventually lost a rod and a main bearing. Now granted it was a different time and era for prices and manufacturing. It was not uncommon to buy a late model used car in the 50's that was from the 30's or 40's that you were lucky to be able to get about 1000/miles per quart of oil but advancements in air cleaner and piston ring technology changed that. I rarely needed to add a quart of oil to the engine between 4000 mile oil change intervals and recently using Mobil 1 and changing a filter at 4000 miles and adding a quart of oil to replace that which was lost via the filter change was all the oil consumed for the 12,000 miles I left the initial Mobil one oil in the engine.
But a little research is showing a number of manufacturers that have developed a reputation for using a quart of oil or more under a 1000 miles of driving.
And surprising enough the recommended oil to be used in those vehicles is a 0W20 or 0w30 oil.
To me that is a very chilling statistic.
So for the time being, my 2015 Dodge Grand Cherokee with a 0w20 oil recommendation is using 10W30 Mobil 1 synthetic oil, an oil that the Viscosity vs Ambient temperature charts say is a viable oil to use for the temperature range I live in. That of 32 degrees to 115 degrees. There is some indication that in doing so the variable cam shaft technology used by that engine will log errors. I have not taken the time to look for them yet. But in my world, an engine that is getting 1000 miles/QT of oil is wearing out. So I question the recommendation of such an oil that reflects light weight.
Historically as an engine wears, increasing the viscosity of the oil used will enhance lubrication and extend the service life of the oil. And the engine.
If I am going to error in selecting an oil to use I intend to error in the direction of a heavier weight oil. Going the other way has caused me to loose engines and if I am going to start having to deal with this on a less than a one year old car I am going to question the recommendation of using a light weight oil in the first place.
More research is needed.
COSCO recently had a sale on in the automotive oil and 3 cases of 6 quarts per case of MOBIL-ONE 10W30 costs the same as one case. My Dodge holds 6 quarts +1 with a Filter. It is a new engine with variable cam shaft technology a part of it.
Time for more research.
Oh and my Saturn with 110,000 miles, a 94 SC2 does not use oil between changes. I use 20W50 in it.

 

Glad to see this post. My 2002 Saturn SL1, I found, is using just about that ratio you mention- 1 qt/1,000 miles. I was quite surprised because none of the Saturns we have owned have used oil like that. I'm going to go to that 20W-50 as you have, and see how that works. It doesn't make sense to me either, to go to such a light oil as 0W-20 or 0W-30. No way! I had a rotary engine Mazda and that HAD to use about 1 qt per 1,000 miles or the seals would burn out. Thanks for the info!

 

I don't pay any attention to the manufacturers RECOMMENDED oil viscosity. I use Castrol Syntec 10W-30 in my 2013 Chrysler 200. I add about a half quart between 7,500 mile changes. In my 03 PT Cruiser Turbo, I run conventional Castrol 10W-40. I use about a quart between 5,000 mile changes. The 200 has 114,000 miles on it now. The PT has 138,000 miles on it.

 

I did pay attention to the recommended viscosity when I first got the car last fall, but no more!
Thanks for the input!
RK

 

I personally think the viscosity you use should be based on the way you're using the car and the climate you live in, Ron. If you live in a hot climate year round like Unc and I do, then you're going to need a thicker oil. That thin crap is just TOO thin IMHO.

 

5w- anything is too thin IMHO too!

 

Keep in mind when thinking of the viscosity of the oil you are choosing to use:
1. Excessive oil consumption is an indication of engine wear. Using a heavier viscosity of oil does not correct wear, but it does slow down additional wear and oil consumption should also reduce.
2. The first number indicates performance in lower temperatures.
3. The second number indicates performance at higher temperatures
4. Thus a "window" is identified. The proper oil to choose is the one that best fits in the temperature window you drive in.
5. An engine that tends to run HOT might take advantage of better lubrication of a higher viscosity oil and thus run cooler.

The factory recommends an oil to be used. The window it chooses is not identified. However in owners manuals or service documents additional information to look at an evaluate are available but it is still incomplete.

This chart and others are in Centigrade. Freezing in "F" 32F = 0C. 104F = 40C and 212F = 100C or Boiling.
Thus the "window" to be chosen is fairly simple to identify. Also heavy duty applications generally require a heavier viscosity rated oil. As engines age and wear a heavier oil is also generally a good idea. A lighter viscosity oil does give better fuel mileage however the unknown in this concept is how much better and can it be measured? Factory warranties are generally 30,000 miles and then they are no longer responsible. So used cars are the responsibility of the owner.

 

That's a lot of good information, UnclJohn. 20W-50 is what I was thinking of using, like you do in your Saturn. Mine has about that same mileage on it now.

 

20W-50 is pretty heavy. I'm running 10W-40 in my turbo. Like I said, it uses about a quart between changes. I'm happy with that.

 

Dodge engine -- there's your problem right there!

The Honda Gods have written in their bible for me to feed my Accord 0W20. They also recommend following the maintenance schedule dictated by the car, and I should change my oil once a year (!) if not told by the car to do so. Right now, I'm sitting on about 4000 miles since the sticker says it's been done. Oil life thingy says it still has 40% oil life left (whatever that means) and to change it when it reaches 20%.

I rest my faith with the Honda Gods and their good book. Clearly they have better minds than mine.