Placebo vs. Engine feels "faster" on 40 than 50

[HangerHarley]

OK. My Experimentation on xW-40 vs xW-50 leads me to conclude: My Engine feels "Peppier" on 40 than 50. Slightly. Im evaluating if it is the Placebo effect.

Oil pressure aside (My car has a gauge, the 94 Probe, seems to be about the same, i may have underfilled a quart, 4 vs 5, not sure if that would affect OP) the OP seems to be the same.

I went back to Maxlife 10W-40. My engine was fairly happy, aside from some Consumption. I pulled off some vacuum hoses, and they were slightly Oily. Maybe i had too much; maybe it is Blow-By

or maybe it was always like that.

Anyways, i just did a fast Oil Change on a Hot/Warm engine and put in the 10W-40. One of the 4 quarts was 20W-50, to make it a xW-"45." (Happy Medium.)

So, my question is: Is it just me, or does the engine "Like" 40 better than 50?

Car seems to be performing OK. Only cause for alarm is when i check the oil hot. I will let a drop drip in the hot Catalytic Converter or Exhaust, and i -sometimes- see Steam, where the Oil fell. That is all that alarms me.

Thoughts?

94 Probe, ECM Chipped, aftermarket Exhaust and some go-fast stuff, 5-speed and 175,000 miles, a good part of them "beater" miles, possible Sludgy inside, im toning down the "De-sludge" and focusing on the "Seal-up" at this time, its had plenty of MMO and stuff in it.

Im afraid of M1 for its reputation as being a "leading leaker" in engines, from more people than not. Though it otherwise seems excellent.

 

[mechtech2]

Sounds right.
Smaller engines really respond differently to oil viscosities.
Even going from a 5-20 to a 5-30 can have 'feel' and very real consequences for power and gas economy.
Why? Because there is less drag, and less work for the oil pump.

 

[ARCOgraphite]

No placebo going down from a 50 wt. Thinner oil is proven to yield more power. The placebo guys would chime in if you say brand X 40 weight is much peppier in my engine than brand Y 40 weight. Now within a specific grade certain oils are proven to yield more power, as in: paraffin vs napthenic, branched vs straight chain, fatty ester vs wax .... This is the magic of the learned, old school blender back in the grp I days. Next, try a thick 30 and disregard the burning

 

[HangerHarley]

Originally Posted By: mechtech2
Sounds right.
Smaller engines really respond differently to oil viscosities.
Even going from a 5-20 to a 5-30 can have 'feel' and very real consequences for power and gas economy.


Good Consequences?

Basically, all is well. If my Oil Gauge (yes i have one) does what it did 3 months ago when i used 10W-40 (reads 60-ish on road instead of 75-ish or 80 on the road on Highway) and I can figure out why i sometimes (not all the time) see Steam from the drop of Oil (This concerns me, should it?

) and sometimes do not, then aside from the semi-Oily PCV Vacuum system, my car seems OK.

Surely, there are cars much worse off.

Im becoming less worried about possible Sludge. As long as i dont knock it loose, im sure it will be fine in there forever, if i dont provoke it like this guy with the Stick

Besides, Sludge seals.

This is my Probe update. Seems to be settling in to a nice, functional pattern. Surely, no cause for concern?

 

[SuperDave456]

I can tell a difference between a xw30 and a xw40 in my 6cyl Vulcan engine on my '02 Ford Taurus. It loses a bunch of its pep when you start going to heavier weights.
It has to do with the drag the heavier oil creates. Althought the engine is much more quiet with a 40 weight than a 20 weight, the difference between the two when you floor it on a short on-ramp to the highway is noticable.

I would stay away from 50 weights unless you are really racing it, at 175,000 miles in a beater it won't last long if you are. 4 Cyl engines typically "feel" better with lighter oils.
I have a difficult time sticking with 20 weights, as I always find the xw30's and xw40's on sale.

Edited to add: BTW, exhaust and Cat's are redicliously hot. If you drip oil on any of it it will burn off. Speed of the burn off directly correlates to how hot it is.

Oily vacuum systems, and PCV valves happen, unless your system is filled with oil or clogged with sludge I wouldn't worry about it. A little oil is acceptable.

 

[aquariuscsm]

My car with different oil vicosities:

50 weights have the smoothest/quietest startups,especially on a long sitting,unstarted engine. Driving feels a bit sluggish while engine is cold,BUT once it`s good and hot,it`s the smoothest and most responsive on these weights.

30 and 40 weights,most responsive cold engine acceleration,but once it`s good and hot,not as smooth and powerful as a 50 weight.

Best oils imo,with my experience in different conditions:


Mobil 1 15W50,best when cold.

Pennzoil dino 20,25W50 weights,best when good and hot and driven hard and fast.

Definitely not placebo when a cheap $2 dollar oil works beter than an $8 dollar synthetic.

But just take this as my opinion and observation,and not scientific fact.

 

[HangerHarley]

Originally Posted By: aquariuscsm
My car with different oil vicosities:

50 weights have the smoothest/quietest startups,especially on a long sitting,unstarted engine. Driving feels a bit sluggish while engine is cold,BUT once it`s good and hot,it`s the smoothest and most responsive on these weights.

30 and 40 weights,most responsive cold engine acceleration,but once it`s good and hot,not as smooth and powerful as a 50 weight.

Best oils imo,with my experience in different conditions:


Mobil 1 15W50,best when cold.

Pennzoil dino 20,25W50 weights,best when good and hot and driven hard and fast.

Definitely not placebo when a cheap $2 dollar oil works beter than an $8 dollar synthetic.

But just take this as my opinion and observation,and not scientific fact.


Interesting!

What car?

 

[aquariuscsm]

Originally Posted By: HangerHarley
Interesting! What car?


The car in my sig,a 1996 300ZX. Nissan engines seem to prefer thicker oil. I know a few who have the twin turbo models (mine`s the non-turbo) who are in the 300,000 mile + range. They all run 20W50 year round (GTX or yb) and still have the original turbos and factory spec compression in all 6 cylinders. They race and regularly track their cars. The VG30DE engines are way different than an American V8. They`re not low rpm torque monsters like a Mustang or Camaro. They don`t reach their power till you hit the 3000-4000 rpm range. I can break the rear wheels loose in 5th gear if I`m over 4000 rpm on the highway.

 

[TallPaul]

I do believe that one would feel a difference between a 20w50 and a 10w30 or 5w20 if their engine was not all that powerful, so that the extra drag was a significant effect on overall power.

 

[fdcg27]

I have observed that the Accords are slower to rev on 15W-50 than they are on XW-30.
I don't think there is any real loss of peak power, it just takes longer to get there.
I think you mainly lose a little mid-range grunt, of which Hondas have precious little to begin with.
Another factor during hot weather is that neither Accord disengages the A/C compressor clutch on full throttle, so the noticeable drag from the compressor is always there, unless you turn the A/C off and sweat.
So, I think that what you are seeing in changing from from a -50 to a -40 is real.

 

[ItsuMitsubishi]

Hanger, do you have a ZE? Either way the KL's really don't like thick oil, 40 is pushing it IMO and 50 is way unreasonable! Why would you need such a thick oil? I had an old 300K DE a while back and it burned all oils about the same. Oil control rings were well stuck... 5w20 in fact burned the slowest, although I tried everything, even lugging and stalling the engine out to turn it off in an attempt to try and "rough up" the rings a little. It still saw the rev limiter each day, it was when the water pump went that I pulled the engine.

 

[HangerHarley]

Originally Posted By: ItsuMitsubishi
Hanger, do you have a ZE? Either way the KL's really don't like thick oil, 40 is pushing it IMO and 50 is way unreasonable! Why would you need such a thick oil? I had an old 300K DE a while back and it burned all oils about the same. Oil control rings were well stuck... 5w20 in fact burned the slowest, although I tried everything, even lugging and stalling the engine out to turn it off in an attempt to try and "rough up" the rings a little. It still saw the rev limiter each day, it was when the water pump went that I pulled the engine.


Dude!!! The Probe is just the little 2.5 DOHC unit with a Chip in it. Now, talking about Nissans, I had a KA24E (NOT the DE, this Probe is DOHC the Nissan was SOHC) and That car was.. beastly. Love love looved it, and yes that got 10W-40 as well.

My Probe likes to sip on my Oil as if it were Tea. No idea whewre it goes, but the PCV System was oily

Hence, Heavy Oil finds home in the Sump.

40 seems like a good balance. 50 can work, however its slightly Revvier on 40, and my post was aimed at if that was real, or imagined.

Seems the Engine is well protected on either of those.

btw.. i dont like the Probe all that much. Nissan 240SX Trumps it. Hands down.

 

[ItsuMitsubishi]

haha By ZE and DE I was talking about the KL V6 in your Probe. It was a big thing for people to dump the KL-DE and replace it with the KL-ZE from Japan ~200 horsies. 300whp on 7psi!


But you're totally right about the Probe vs 240. It's FWD vs RWD and theres no comparison. KA's are very well suited for boost too, even on stock rods! My buddy had a boosted KA 240 on 20psi and that thing pulled like a scalded horse!!

 

[Spyder7]

Originally Posted By: ItsuMitsubishi
Hanger, do you have a ZE? Either way the KL's really don't like thick oil, 40 is pushing it IMO and 50 is way unreasonable! Why would you need such a thick oil? I had an old 300K DE a while back and it burned all oils about the same. Oil control rings were well stuck... 5w20 in fact burned the slowest, although I tried everything, even lugging and stalling the engine out to turn it off in an attempt to try and "rough up" the rings a little. It still saw the rev limiter each day, it was when the water pump went that I pulled the engine.


Have a similar issue (oil consumption still fairly low). 5W30 is spec`d for mine and I`ll stick with 5W30. 40 or 50 weight oil, no matter how bad the consumption gets, is out. I don`t mind playing around with different oils within that viscosity, but my car will never see anything thicker than a 30 weight oil. I`d consider a switch to 0W30 oil for winter - if whatever I was looking for was available in that grade. But that`s the only change I`d consider.

-Spyder

 

[mechtech2]

The good consequences include:
Better flow at start up when cold, better cooling of internal engine parts, likely lower oil operating temperature under the same conditions, power is freed up, and better gas mileage.