switching from 5W30 to 5W20

[Jeff_in_VABch]

Originally Posted By: tig1
Originally Posted By: Steve S
What will a 5w-20 do better than a 5w30?


Slightly lower oil temps. Quiter valve train. More shear stable. When was the last time anyone saw 0 or 5-20 shear down? I'm not saying it can't happen,but....



Oil viscosity vs. oil temperature would be an engine specific parameter which could be higher or lower depending on engine design parameters such as oil pump type and bearing clearances. There is no way to generalize this, particularly with oils in a fairly close viscosity range.

Quieter valve train? Not sure of the valve train design on the OPs engine, but generally, the higher the oil pressure, the lower the noise, as there is more vavetrain oil flow at higher pressure to the top of the engine.

By nature of basic oil properties, any lower viscosity oil is more shear stable than a higher viscosity one. It is just not possible for it to break down as far on a percentage shear basis.

 

[lexus114]

Originally Posted By: Jeff_in_VABch
Originally Posted By: tig1
Originally Posted By: Steve S
What will a 5w-20 do better than a 5w30?


Slightly lower oil temps. Quiter valve train. More shear stable. When was the last time anyone saw 0 or 5-20 shear down? I'm not saying it can't happen,but....



Oil viscosity vs. oil temperature would be an engine specific parameter which could be higher or lower depending on engine design parameters such as oil pump type and bearing clearances. There is no way to generalize this, particularly with oils in a fairly close viscosity range.

Quieter valve train? Not sure of the valve train design on the OPs engine, but generally, the higher the oil pressure, the lower the noise, as there is more vavetrain oil flow at higher pressure to the top of the engine.

By nature of basic oil properties, any lower viscosity oil is more shear stable than a higher viscosity one. It is just not possible for it to break down as far on a percentage shear basis.



So what do you think Jeff? Does it hurt to try it?

 

[tig1]

Originally Posted By: hypervish
But, the Lexus is safe to run 5w-20, but I just wouldn't recommended it right now (heat wave). Switch to 5w-20 before winter starts.


We are having the hottest temps since switching to 0-20(high 90s to low 100s for days now) and the engine is quite and smooth.

 

[steve20]

Originally Posted By: tig1

But, the Lexus is safe to run 5w-20, but I just wouldn't recommended it right now (heat wave). Switch to 5w-20 before winter starts.


We are having the hottest temps since switching to 0-20(high 90s to low 100s for days now) and the engine is quite and smooth. [/quote

they are all like that-real quiet ---just before they put a rod through the side of the block, small end first--- j/k I had to, your infatuation with 0-20 made me do it

 

[odie]

Then why would TOYOTA , HONDA , and other car manufacturers go to 5w-20 and 0w-20 for new and older models ? To get more wear ?

 

[odie]

Originally Posted By: odie
If the Shell 5w-20 syn is used , I'll likely get an U.O.A. for it in the spring of '12 .
Here's the Product Data Sheet for the SHELL SN/GF-5 posted JUNE 2010 . What's your take on the 5w-20 ?

 

[Clevy]

Sounds like your going backwards as far as protection

 

[lexus114]

Originally Posted By: Clevy
Sounds like your going backwards as far as protection



I used to believe the thicker oil was the better oil.In 1980 all I used was 10W40 Quaker State,and Shell Fire & Ice. Then when I got my Monza (2.5l Pontiac motor) I used 20W50 Castrol GTX of course. Because in those day`s GTX was rated for small 4cyl engines. Anyway, then I became wise to the fact that the best oil to use (for non turbo/towing apps.) is the thinnest oil the motor will allow. Easier cold starts, easier pumping for the oil pump, less drag on the motor. All equals more torque, better fuel economy.

 

[Jeff_in_VABch]

Originally Posted By: lexus114
[

So what do you think Jeff? Does it hurt to try it?


As long as your engine develops good oil pressure with the XW20 oil, it will be fine when operated appropriately.

However all things are best when used in moderation. If this were a winter time change, I would be all for it, heatwave in summer, not so much.

Drag race engines use very light low detergent oils, some are as light as 2WT. I ran 5WT and 10WT as a test in an engine on the dyno and the gain was very minimal over a 30 WT. From a power or economy standpoint, going from a XW30 to a XW20 oil probably makes (didnt test this combo) a measureable difference in power, but I cant see it being worth it at all.

If you want to make a real difference in power or economy, change the engine tuning.

 

[lexus114]

Originally Posted By: Jeff_in_VABch
Originally Posted By: lexus114
[

So what do you think Jeff? Does it hurt to try it?


As long as your engine develops good oil pressure with the XW20 oil, it will be fine when operated appropriately.

However all things are best when used in moderation. If this were a winter time change, I would be all for it, heatwave in summer, not so much.

Drag race engines use very light low detergent oils, some are as light as 2WT. I ran 5WT and 10WT as a test in an engine on the dyno and the gain was very minimal over a 30 WT. From a power or economy standpoint, going from a XW30 to a XW20 oil probably makes (didnt test this combo) a measureable difference in power, but I cant see it being worth it at all.

If you want to make a real difference in power or economy, change the engine tuning.




Thanks for the reply Jeff. Appreciate it.

 

[bigdawg74]

Originally Posted By: Jeff_in_VABch

What part of the country are you in? Part that is in the current heatwave?



Oh, so not in Seattle then. Forecast to be partly sunny today w/ a high near 71. Lows in the lower 50s.

 

[odie]

Originally Posted By: odie
Originally Posted By: odie
If the Shell 5w-20 syn is used , I'll likely get an U.O.A. for it in the spring of '12 .
Here's the Product Data Sheet for the SHELL SN/GF-5 posted JUNE 2010 . What's your take on the 5w-20 ?
Oops , forgot the P.D.S. . Had one of those lapses . Here it is , http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140003596099_201007081845.pdf .

 

[JOD]

Originally Posted By: bigdawg74
Originally Posted By: Jeff_in_VABch

What part of the country are you in? Part that is in the current heatwave?



Oh, so not in Seattle then. Forecast to be partly sunny today w/ a high near 71. Lows in the lower 50s.

Summer was awesome, wasn't it. You know, that day a couple of weeks ago when it hit 80 for an hour??

If ever there were a place to leave with a leaky air compressor on your car, this is it...

 

[bigdawg74]

Originally Posted By: JOD

Summer was awesome, wasn't it. You know, that day a couple of weeks ago when it hit 80 for an hour??

If ever there were a place to leave with a leaky air compressor on your car, this is it...

I was at work, so I missed it. Speaking of which, I work for Home Depot in the distribution center here. We have been receiving shipment of snow blowers since last week. Should have fireplace accessories and heaters coming in by the end of this week. Christmas stuff (trees/decorations) due in August. Jingle Bells, Jingle Bells...

Ok, I apologise for getting off topic...

 

[lexus114]

Originally Posted By: bigdawg74
Originally Posted By: JOD

Summer was awesome, wasn't it. You know, that day a couple of weeks ago when it hit 80 for an hour??

If ever there were a place to leave with a leaky air compressor on your car, this is it...

I was at work, so I missed it. Speaking of which, I work for Home Depot in the distribution center here. We have been receiving shipment of snow blowers since last week. Should have fireplace accessories and heaters coming in by the end of this week. Christmas stuff (trees/decorations) due in August. Jingle Bells, Jingle Bells...

Ok, I apologise for getting off topic...

 

[ARCOgraphite]

Originally Posted By: hypervish
But, the Lexus is safe to run 5w-20, but I just wouldn't recommended it right now (heat wave). Switch to 5w-20 before winter starts.
A liquid-cooled passenger car running with a "normal" engine load (read: varies light-moderate) will not see the ambient temp. Be it 60 degreses or 105F. Just because you are hot does not mean the oil is

The oil sump temp is more engine load dependent - when you start putting heat into the oil faster than the block and pan can remove it then you'll see temps climb. 5w20 multigrades can be vastly superior to the notorioulsy unstable, deposit prone 5w30.

 

[rcy]

lexus114, as you know from over at the Lexus forums, I've been running Toyota 0w20 in my 400h for the past two winters. I DO plan to run it all year, but I had a couple jugs of 5w30 I had to use up over the last two summers. Now, I recently got some Pennzoil Ultra 5w20 on sale so I will probably use that next summer.

My experience running the 0w20 in the Lexus - nothing to report. Car runs the same - it might be a bit smoother at start up than with the 5w30. I've done a used oil analysis and the results are posted somewhere around here. Good results.

It hasn't thrown a rod through whatever blah blah that someone else posted. I also don't baby this vehicle - I like the surge of power when the electric motors and engine are all working at the same time (the passing performance of this vehicle is exemplary).

 

[rcy]

Originally Posted By: ARCOgraphite
Originally Posted By: hypervish
But, the Lexus is safe to run 5w-20, but I just wouldn't recommended it right now (heat wave). Switch to 5w-20 before winter starts.
A liquid-cooled passenger car running with a "normal" engine load (read: varies light-moderate) will not see the ambient temp. Be it 60 degreses or 105F. Just because you are hot does not mean the oil is

The oil sump temp is more engine load dependent - when you start putting heat into the oil faster than the block and pan can remove it then you'll see temps climb. 5w20 multigrades can be vastly superior to the notorioulsy unstable, deposit prone 5w30.


I was just about to post that if you have a...say...180 degree thermostat, what difference does ambient temp make if the system is designed to keep the coolant at 180 (and subsequently, I'd assume, the oil will stay at some constant temp as well?)

 

[crazyoildude]

i am a believer in 5w20 also...
good stuff

 

[virginoil]

Don’t join the anorexia engine oil club.

Going thinner is not always best. Mileage increase is barely measurable.

Like its been said in earlier posts what will a 5w20 do other than increase the risk of ............ ?

It’s a knuckle head thing to do, IMO, considering the mileage and no problems to date.

As the adage says, if you are on a good thing stick to it. I've learnt the hard way.