Changed Auto Engine Oil. Runs Smoother?

[wolf]

Real simple question. Been changing my Auto engine oil for past 50 years.

Seems, right after the oil change, Auto seems to run smoother and quieter.

Has anyone else experienced this? Or is it just psychological?

Anyone, do any real experiment with data?

 

[Jager]

I've experienced the same thing on my bikes and cars.

It's just a nice psychological boost.

 

[sailor]

Not for me. Have not noticed this on cars or airplanes.

 

[Senator]

I change my own oil too, and noticed the same thing. I do not see how it can be actual, as the old oil is still functional.

I too think it is just psychological.

 

[frank]

I changed my own oil on my trucks, cars, and bikes for many years and think it is psychological. it used to be fun and got some satisfaction out of it but as you get older not so much, as you can look around and get an oil change coupon at a local dealership almost cheaper than you can buy the supplies.

 

[Texas Proud]

Back when I used to change myself.... never noticed a difference...


Paying for it... again, no difference...


I would bet that you could not even measure a difference with technology that could tell much better than the 'butt method'....

 

[txtig]

I always thought my vehicles ran smoother right after I washed them!


Sent from my iPad using Early Retirement Forum

 

[eytonxav]

I don't think this is a psychological phenomena, but simply due to oil loss and/or old oil breaking down causing rougher running, especially if it hasn't been changed in a while. So an oil change can make it run smoother.

 

[easysurfer]

Feels that way. But may just be the placebo effect.

 

[Car-Guy]

I've changed the oil myself in all my cars and motorcycles for "almost" 50 years now and have never noticed a difference in smoothness or quietness.

 

[RockyMtn]

I always thought my vehicles ran smoother right after I washed them!


Sent from my iPad using Early Retirement Forum

+1

 

[robbridg]

Or is it just psychological?

this


Unless you're waiting too long between oil changes.

 

[Andre1969]

I've never noticed it, myself, after an oil change. However, if your oil was a quart or two low before you changed it, maybe that would have an effect? I don't think oil really breaks down anymore like back in the old days, but it probably still gets moisture and other contaminants in it, especially as a car ages.

The only time I ever heard of a big change was after putting in a different weight oil. My Granddad did a lot of mechanic work, and worked on a lot of his friends' cars. Well, one couple had a 1982 Bonneville G with the Buick 231 V-6. It always seemed to run like crap. Well, they had been putting 10W-30 oil in the car, but Granddad changed it to straight-30, and they said the car ran better.

Don't know if that was true or not, but I just remember Granddad mentioning it, and swearing by straight-30 almost til the day he died. He didn't trust those multi-weight oils. And, in those days, I don't think they were as good as they are today.

As for why they thought that engine ran like crap, well in those days, some of those V-6 engines were simply a V-8 with two cylinders lopped off. A 90-degree V-8 is naturally balanced, but a 90-degree V-6 is not. So, to someone used to the sound and feel of a V-8 engine, one of those V-6es might feel and sound like it's out of tune.

In the long run, I don't know if that heavier weight oil would have done more good or harm to that engine. Those early Buick 231's weren't very durable engines, to begin with, although once all versions started using the turbo block for 1985, they went from being one of GM's crappiest engines to one of its best.

 

[springnr]

As a kid, I remember possessing the ability to run faster and jump higher upon donning newly acquired;

 

[bjorn2bwild]

I am pretty sure Slick 50 and the like make a tidy sum on the perception vs reality trade.
i.e. - the effect is most pronounced with snake oil.

 

[mystang52]

As a kid, I remember possessing the ability to run faster and jump higher upon donning newly acquired;

Being a chubby boy, and to this day never being particularly agile, was I disappointed when these sneakers did nothing for me!

 

[Andre1969]

I am pretty sure Slick 50 and the like make a tidy sum on the perception vs reality trade.
i.e. - the effect is most pronounced with snake oil.

One morning, back in the early 90's, when I was still in college, I decided to drive my Granddad's '85 Silverado to school. He had passed away, and the truck just sat around, rarely used, so I'd drive it once in awhile just to blow the cobwebs out. Well, one morning, after it had sat a couple weeks, I started it, and it sounded really rough. The oil pressure idiot light that's supposed to come on for a moment just to let you know it works did not go off. So I shut it off almost immediately. Checked the dipstick...dry as could be.

I looked underneath, and found that the drain plug was loose, and there was a slick spot on the grass. By this time I was running late for class, so I just took my car and left the truck til later.

I told my uncle about it, and found out what apparently happened. He had taken it to some quickie lube place for an oil change, and they must not have put the drain plug on tight enough, so while it sat in the yard, it leaked out. My uncle also said not to worry, because he had put some Slick 50 in it!

I'm sure the Slick 50 did no good whatsoever...we just lucked out that the oil leaked out while it was parked, rather than have the drain plug rattle loose and dump it all out at highway speeds or something. But, that was over 20 years ago, and we still have the truck. Still runs...for the most part.

 

[W2R]

Seems, right after the oil change, Auto seems to run smoother and quieter.

I always thought this, too, but have been told numerous times that this is a "girl thing", totally my imagination and not possibly in any way ever a real phenomenon.

 

[GrayHare]

This can happen with a change in oil weight. Maybe the fresh oil is a different weight than what you drained.

 

[aja8888]

After 50 years of changing oil in my vehicles, I now notice a quieter engine. But, then again, my hearing is pretty much shot and I haven't gotten hearing aids yet. (notice in my avatar the use and consumption of Marvel Mystery Oil - the stuff is great! (smells good too)).

 

[manerac]

This can happen with a change in oil weight. Maybe the fresh oil is a different weight than what you drained.

Yep, viscosity drops with miles, valves are quieter with fresh oil.

 

[M Paquette]

Heh... It may run quieter, for certain types of engine construction and wear. I had one vehicle where the camshaft and valve lifters were located low and to one side, almost below the oil fill cap. Hydraulic 'self adjusting' lifters rode on the camshaft, and in turn shoved the valve pushrods. The lifters were in wells, which filled up nicely when oil was added to the engine.

When the lifter is not under pressure, a strong spring causes it to open or lengthen, drawing in oil normally supplied through a channel in the surrounding assembly and a hole in the lifter body. When the camshaft turns to open the valve, it pushes on the lifter, which closes the hole, trapping the oil inside and transferring lifting force to the valve pushrod. If all goes well, your engine runs with 'zero clearance', no gap between the parts in the valve push path, and no clicky noises from valve lash (that gap).

In an older, worn engine the oil supply to the lifter may be marginal from crud in the oil channels, or from wear around the lifter letting more oil dribble out. If the lifter isn't solidly filled with oil, it will allow a little space in the valve push path, which you'll hear when the engine is started as a bit of 'clicky' noise on top of the normal operation. In older engines you'll hear this noise for a little while until the engine warms up and the oil starts to move more freely to the lifters.

When you add oil to the engine, the lifter wells are full of cold, viscous oil before you even start the engine. The lifters fill up right away, and all that oil around them also damps the noise a bit.

Don't worry, though. Your engine will be back to it's old, clicky self the next time you start it up cold.

 

[bjorn2bwild]

This same question was asked on the 'bob is the oil guy' forum with no clear consensus.
Perhaps an engine rigged with an array of accelerometers could answer the question with more authority?

Explain How Oil Can Make An Engine "Smoother" | Passenger Car Motor Oil (PCMO) - Gasoline Cars/Pickups/Vans/SUVs | Bob Is The Oil Guy

 

[38Chevy454]

I agree most is placebo effect, you think it is so therefore you conclude that.

However there are a couple scenarios that it can be true for temporary effect:
1) Engine is warm, but the new oil is cooler, so it is a bit thicker and therefore may be a little quieter initially
2) Oil does tend to break down and get thinner viscosity when it is used. The base oil in multi-viscosity oil is thinner and then the multi-viscosity elements make it thicker with temps. These thickener additions get used up/wear out over time. Some engine applications have more shearing effect which accelerates the viscosity thickeners getting used up faster. New oil has the full capacity thickeners when new.

While it is true the basic oil does not wear out, what does happen is your oil gets dirty and loses the additives as it is used. Both reasons to change it out. The oil filter does not get all of the contaminants out, the oil is supposed to hold some of the smallest particles in suspension.

 

[eytonxav]

Where are the engineers that can use logic to solve problems. Oil reduces friction and protects your engine from ware. If your engine consumes oil, and the impurities build up and the protective properties in the oil are used up over time, more friction will be created. More friction = noise and less smooth operation. Probably inperceptible if you change your oil as specified in your owners manual and/or if you top up should your engine consume oil, but if not, you are likely to discern a difference. I've seen this happen often when folks do not change their oil regularly or its down a quart or more.