From an untrained BITOG ear

[ProfPS]

I finished a 5k OCI of Pennzoil Platinum 5w30 in my wife's car and replaced it with Hav DS from my stash. When I started the car my 10 year old don quickly said on his own that the engine sounds better. I was surprised that he noticed.

I will say that after a 500 mi trip (250 mi each way with cruise set at my normal interstate cruising speed) I did not notice a difference in highway MPG from Pennzoil conventional, Pennzoil SUV, or Chevron Sup; city driving no notable difference either. The car continuously gets 32-34 highway MPG on the car's computer; actual calculated is 2 MPGs less - for me no difference between dino & PP with my driving style.

 

[bluestream]

Any new room temp oil put in is thicker than the hot sheared down stuff that came out.

People interpret this as "engine runs quieter" or "my car liked it"

 

[ProfPS]

Originally Posted By: Bluestream
Any new room temp oil put in is thicker than the hot sheared down stuff that came out.

People interpret this as "engine runs quieter" or "my car liked it"



Hence the subject of the thread and my 10 year old son's vast experience on this subject.

 

[daves87rs]

Originally Posted By: ProfPS
Originally Posted By: Bluestream
Any new room temp oil put in is thicker than the hot sheared down stuff that came out.

People interpret this as "engine runs quieter" or "my car liked it"



Hence the subject of the thread and my 10 year old son's vast experience on this subject.

 

[GMorg]

Bluestream wrote: "Any new room temp oil put in is thicker than the hot sheared down stuff that came out."


Since many oils will actually increase in viscosity with continued use, I don't think that the statement above is universally true. On the other hand, if the core of comment has nothing to do with shearing but instead is focused on hot oil verses ambient oil, then it may be accurate.

 

[bluestream]

Originally Posted By: GMorg
Bluestream wrote: "Any new room temp oil put in is thicker than the hot sheared down stuff that came out."


Since many oils will actually increase in viscosity with continued use, I don't think that the statement above is universally true. On the other hand, if the core of comment has nothing to do with shearing but instead is focused on hot oil verses ambient oil, then it may be accurate.


Yes, they can increase in vis with use as they oxidize. The OP mentioned 5K OCI, so I doubt we are in Oxidization yet.

 

[KrisZ]

I noticed lately that some people dismiss "butt dyno" feel a lot on this board, coming from car enthusiasts I find it really strange. While I agree that judging the engine by "ear" is not too scientific and different people are more tuned than others, but at the same time we cannot dismiss all these accounts as just placebo effect, especially when someone owns the car for a long time and knows the sounds it makes. I notice similar attitude with a lot of techs and mechanics, if there are no codes, then it must be normal even though the car doesn't run right, or doesn't feel right.

Back in carburetor days a good mechanic could tune the car just by ear, would some of you dismiss his abilities as well?

But some things can be just a placebo effect as well. For example my car always sounds quieter and seems to run smoother right after the oil change, but after a day or too, it fells exactly the same as before, so I know that it's placebo in my case, but other cars may react differently to new oil.

 

[mechtech2]

The average person's threshold of realization is about 10%.
Being interested or involved is a subject makes this threshold less.

 

[ottotheclown]

I always think after reading threads like this if these opinions were coming from someone who really know something why are they taking time on the internet???? It cannot be from those who know. Like if you are so smart how come you aint rich?????

 

[[RT] ProjUltraZ]

i say thanks, the next step is to do back-to-back 1,000 mile tests