OT: reduced oil consumption with 5w20 oil?

[ryan roopnarine]

first things first, this isn't with any bmw motor, i'm sure that one of those would be clacka-clacka-clacking within two changes if you attempted to use such a light oil in such.

the vehicle in question is a 1999 ford taurus with 150k miles on it. i was changing the oil on two vehicles with the ford vulcan 3.0 v-6, the aforementioned taurus, and a 1998 ford ranger with 205k miles. i was in a hurry to go over and mow my grandmother's lawn, so i attempted to change the oil in both at the same time. here's where my story starts. i had previously bought a number of bottles of 5w20 quaker state to try out in the taurus, as ford has retroactively approved the use of xw20 oil in vehicles that required an xw30 in 2002. bill r had said something to the effect that he would not bother trying it out on such an old vehicle, and that i wouldn't notice a gas mileage improvement, which was one of the selling points for the stuff.

in my haste, i accidentally left the drain plug off of the truck whilst refilling it, which caused me to waste 5 quarts of the 10 quarts of the 5w30 necessary to service both vehicle.....long story short, one of the vehicles ended up getting 4.5 quarts of 5w20, as i wasn't in the mood to go back to the store. vehicle was filled up to 1/2 quart below fill mark 4500 miles ago. usual oil consumption was 2/5 -.5 quart between 3000 mile oil changes. checking the level yesterday indicates that the car has used 2/5 of a quart in 4500 miles on 5w20.

i know that oil makers are not yet technologically advanced enough to make a 20 weight oil that is not semi-synthetic, but even when i was using mobil 1 in this vehicle, i'd still see a consumption of 1 quart per 6k miles. any thoughts or explanations as to why my consumption might decrease with this significantly thinner oil? thanks for spending the 15 minutes to read this.

[Ross]

Accuracy measuring tiny fractions of a quart via the dipstick is dubious at best. Attitude of the car, how long it has sat before checking and oil in the tube all contribute to what the indication is. I suspect the oil consumption hasn't really changed.
Driving conditions will contribute as much or more to the consumption as such a minor viscosity change.
I hope you still had a drain pan beneath the car when pouring those five quarts through.

[ryan roopnarine]

let me make something clear, in the event that i obscured it with all of my babbling.

usual consumption is .5 quart per 3k, full crankcase (ie, dipstick goes from F to 1/2 down within 3k, or 1 quart per 6k)

consumption during this change is apparently 4/10 per 4500 miles, with the dipstick filled to halfway between hashmarks at the oil change (ie, filled halfway, has not dipped to below FILL line) within the last 500 miles. i've checked it about 7 times on 7 different surfaces during the last 500 miles to see if the level would drop enough to require refilling--out of curiousity.

we've owned the car since it was about 11 months old (a 1999 car put into service in 10/98, purchased by us in 10/99. i have a significant knowledge of the oil consumption of this car. normally, i would have expected to had to add at least .5-.75 quart of oil (because i like to have it topped off) to the car to make it to a 5k oil change on 5w30. driving has been about 1k miles a week, almost entirely 50/50 city highway, for the past ~three months. it was burning more on 5w30 doing this than it is now.


and yeah, the drain pan was still under there, but my drain pan at my mother's house is a custom job made out of a liquid margarine jug that only holds about 9 quarts. enough spilled out to ruin my day.

[bsell]

...(because i like to have it topped off)...

I think this is the key to the 'mystery'.

You said that on this oil change you left the engine .5 quart shy of full (not normal for this car for many years) as you had better things to do.;)

With this lower oil level, could there be less whipping of the oil by the crankshaft; meaning less frothy oil to be more easily burned, either through the PCV system or past the rings?

The proof of this theory would be to use the 5W-20 on the next oil change and keep the oil topped up as before. If the consumption is less than the old 'normal' with the old 'normal' top-off behavior, then it must be the oil formulation and not my half-baked hypothisys.:D

Happy New Year,

Brian

[ryan roopnarine]

that might be it, now that i think about it. i'm going to go to the store tomorrow, buy some of the $2.75/qt synthetic oil that is on sale at advance auto (the xw20) and fill it up all of the way with a change.

[ryan roopnarine]

i know that nobody cares, but i changed my oil to a full syn 5w30 about a week ago. i thought that valvoline made a syn xw20, and that i would be able to get such on sale for 5.20 for 2 quarts, but no such luck. fyi, the synthetic oils on sale for bogo at advance autoparts are valvoline syn 5w30, 10w30, and 20w50, so they do have something for e34s if one is at all interested in partaking in the sale. anyways, the car has began to suck down the 5w30 as it did in the past. at the next interval, i'll spend the extra couple of bucks to put in a full synthetic 0w20 from mobil 1 and see if the consumption decreases the way it did with 5w20. currently, the car has used about .2 quart on 800 miles of driving.

[bsell]

[QUOTE=ryan roopnarine]i know that nobody cares, but i changed my oil to a full syn 5w30 about a week ago. i thought that valvoline made a syn xw20, and that i would be able to get such on sale for 5.20 for 2 quarts, but no such luck. fyi, the synthetic oils on sale for bogo at advance autoparts are valvoline syn 5w30, 10w30, and 20w50, so they do have something for e34s if one is at all interested in partaking in the sale. anyways, the car has began to suck down the 5w30 as it did in the past. at the next interval, i'll spend the extra couple of bucks to put in a full synthetic 0w20 from mobil 1 and see if the consumption decreases the way it did with 5w20. currently, the car has used about .2 quart on 800 miles of driving.[/QUOTE

So you filled it all the way to 'full' again?

You know, I remember being told a story where somebody's dipstick was too short, causing high oil consumption due to running the engine with the oil in an over-full condition.

Do you know where your dipstick has been?:D

Brian

[philbyil]

These are great....and will save you time (and oil) ;) :D :D


[URL="http://www.quickoildrainvalve.com/"]

[AngryPopTart]

I've always read people say that oil consumption is higher with lighter oil, if you had a consumption problem, because it gets past the rings more easily. So this thread begins to defy what I thought was logical.

On the previous motor of my E34, I would always fill the thing to the spec'd amount, and it would be full, but without fail it would lose enough oil to read half-way on the stick and then stay there.

Edit: I use 20w50!

[ryan roopnarine]

brian, i filled it all of the way up because i thought that there was a possibility that rings had become "unstuck" during the interval, and that maybe consumption would remain the same on 5w30. as soon as this car rolls over 1k miles on the change, i'm going to use my marine lube pump to suck the quantity of oil down to 1/2 from full through the dipstick tube. i really don't like leaving the oil level down any on anything that i drive. i don't recall the exact wording of the saying, but there is a saying that says "lube is cheap, parts are not," or something to that effect. i'm curious to see how this goes though. though the shape of the dipstick handle is different, both the truck and the car have the same motor, so i might try the truck dipstick on the car the next time i'm in orlando.


as to the speed drain valve.....i think that my becoming an old man is going to require one of those soon. too much dropping of plugs into the drain pan and so forth...

[bsell]

I guess another check on your 'dipstick' is if you put the proper volume of oil in the engine after giving her a good draining, you should have had an exactly full reading on the stick. Anything otherwise, then you have either the wrong dipstick, incorrect volume of oil, or a non-stock filter or oil pan.

And you said before there are no leaks, right? Like from a crack in the oil pan that is only reached when the oil leve is topped off?

Either way, something funny is going on. But good old 'process of elimination' should do the trick in the end.

Brian