5w20 vs 5w30

[Gene K]

Originally Posted By: tig1
Originally Posted By: KCJeep
There is very little a 5w20 will do that a 5w30 won't do as well or better. About the only possible advantage to the 5w20 is cold starts and it is small, you can easily find 5w30's with better cold crank abilities than say a 5w20 dino. I will take the 5w30 thank you.


So what's the advantage of a 30wt over a 20wt then? I may very well have been using 0-20 longer than most here,(used M1 5-20 in the late 70s in an engine calling fo 10-30) and have found it to be outstanding in all temps. I like the way my engines start in cold temps and perform in hot temps. My engines use no oil between OCIs and both are very clean through the oil fill hole, so the 20wt isn't showing any signs of oxidizing, or do my engines show signs of wear. This is all at 10K OCI's. Now if my engines called for a 30wt then I would use 5-30 in this day and age. You simply can't prove your point that a 30wt is better for your engine if it calls for a 20. Now opinions are just that, opinions.


Assuming HT/HS follows I can prove 30 grade is better at higher sump temps. However for typical street use it's likely a non-issue.

 

[Gene K]

Originally Posted By: 69GTX
My 2002 calls for a 20 grade. It was designed 10 yrs earlier for 30 grade use and stayed that way to 2000. I'd say that's proof enough that a 30 grade is just fine for that identical engine in 2000 and later models.

Is there any proof that a 20 grade protects better than a 30 grade? Do the OEM's run all their tests out to 300K miles on both grades? If I lived in a warmer climate with mild winters, I'd want the 30 grade for hot summer use. You can do your 1 yr OCI's with 30 grade in spring so that by winter it's sheared down to nearly a 20 grade any ways. Pick a weaker 30 grade to boot.


At 195F Oil Temp and below I would prefer 20. At 215F and above I would prefer 30.
In reality for most of us it's a non-issue.

 

[AuthorEditor]

I run 5W-30 in the Impala, which calls for it, and also in the Sebring which specs 5W-20. The main reason I use the 5W-30 in both is that it is easier stocking one grade for both and I think the 5W-30 is a better compromise, especially with the pushrod 3.4 in the Impala.

 

[tig1]

Originally Posted By: Gene K
Originally Posted By: tig1
Originally Posted By: KCJeep
There is very little a 5w20 will do that a 5w30 won't do as well or better. About the only possible advantage to the 5w20 is cold starts and it is small, you can easily find 5w30's with better cold crank abilities than say a 5w20 dino. I will take the 5w30 thank you.


So what's the advantage of a 30wt over a 20wt then? I may very well have been using 0-20 longer than most here,(used M1 5-20 in the late 70s in an engine calling fo 10-30) and have found it to be outstanding in all temps. I like the way my engines start in cold temps and perform in hot temps. My engines use no oil between OCIs and both are very clean through the oil fill hole, so the 20wt isn't showing any signs of oxidizing, or do my engines show signs of wear. This is all at 10K OCI's. Now if my engines called for a 30wt then I would use 5-30 in this day and age. You simply can't prove your point that a 30wt is better for your engine if it calls for a 20. Now opinions are just that, opinions.


Assuming HT/HS follows I can prove 30 grade is better at higher sump temps. However for typical street use it's likely a non-issue.


It is a non issue because M1 0-20 will not oxidize up to nearly 500F.

 

[circuitsmith]

Originally Posted By: Gene K
Hondas have went 400,000 miles on 5W20 or 20W50. Most models are just not that viscosity sensitive.


Going waaay back I had a 1975 Civic CVCC. No AC, no power steering.
Normally put 10W40 in it.
One summer I went a little crazy and drove it from Wash. DC to Seattle to Tucson & back to DC.
Ran 20W50 for that adventure.
Didn't miss a beat.

 

[asker123]

Was doing some google search on 5W30 over 5W20 specially in high milage vehical like mine ( Well, mine is not high millage but old for sure it is 2003 Accord but only 135000 kms) and mine burns oil also.

I kind of liked this comment on Reddit

https://www.reddit.com/r/MechanicAdvice/comments/3c636e/5w20_vs_5w30_for_a_higher_mileage_motor/

"RickMN 1 point 10 months ago

Higher viscosity oil does coat thicker. But it also flows slower so it can't carry heat away from metal parts (it's #2 job) as well as the factory recommended weight. So it basically wears out your engine faster. That's the myth of using a higher weight oil in a high mileage vehicle. Advice: Use the recommended weight but buy a high mileage oil. It has most detergent and anti-corrosive additives to combat greater blowby due to high miles, and it has a film strengthener to seal better. But it flows like the recommended oil.

Don't second guess the engineers.
"

 

[aquariuscsm]

Originally Posted By: asker123
Was doing some google search on 5W30 over 5W20 specially in high milage vehical like mine ( Well, mine is not high millage but old for sure it is 2003 Accord but only 135000 kms) and mine burns oil also.

I kind of liked this comment on Reddit

https://www.reddit.com/r/MechanicAdvice/comments/3c636e/5w20_vs_5w30_for_a_higher_mileage_motor/

"RickMN 1 point 10 months ago

Higher viscosity oil does coat thicker. But it also flows slower so it can't carry heat away from metal parts (it's #2 job) as well as the factory recommended weight. So it basically wears out your engine faster. That's the myth of using a higher weight oil in a high mileage vehicle. Advice: Use the recommended weight but buy a high mileage oil. It has most detergent and anti-corrosive additives to combat greater blowby due to high miles, and it has a film strengthener to seal better. But it flows like the recommended oil.

Don't second guess the engineers.
"


Haha man Rick must've been smoking something besides tobacco!

 

[gfh77665]

Originally Posted By: asker123

Don't second guess the engineers.


Don't second guess the engineers EPA CAFE MANDATES from the government.

 

[bbhero]

Bingo... Winner winner chicken dinner! CAFE

 

[Shannow]

Originally Posted By: asker123
Higher viscosity oil does coat thicker. But it also flows slower so it can't carry heat away from metal parts (it's #2 job) as well as the factory recommended weight. So it basically wears out your engine faster. That's the myth of using a higher weight oil in a high mileage vehicle.


section in bold is rubbish...

 

[chainblu]

Both, 5w20 and 5w30, are CAFE driven. I thought this was common knowledge...

 

[53' Stude]

0w20 and 5w20 are CAFE driven NOT 5w30 as GM for years used and still does use 5w30 on some stuff.

 

[53' Stude]

"Common sense is not so common anymore"

 

[chainblu]

Originally Posted By: car51
0w20 and 5w20 are CAFE driven NOT 5w30 as GM for years used and still does use 5w30 on some stuff.


That doesn't mean it's not CAFE driven. How long has CAFE been around?

 

[53' Stude]

I don't know and it doesn't bother me. My fleet at work we use 5w30 in everything except what calls for full syn 0w20. We have used 5w30 since the early 90's too without issues

 

[Shannow]

Originally Posted By: car51
0w20 and 5w20 are CAFE driven NOT 5w30 as GM for years used and still does use 5w30 on some stuff.


the ILSAC grades are and were "EC"...same mother just older.

 

[tig1]

Originally Posted By: car51
0w20 and 5w20 are CAFE driven NOT 5w30 as GM for years used and still does use 5w30 on some stuff.


And I used M1 5-20 in the 70s when there was no CAFE. I used it because it performed so well. Also CAFE does not require 0-20 oils.. ever notice how many engines calling for heavier oils than 20WT.

 

[AuthorEditor]

Quote:
Also CAFE does not require 0-20 oils.

I think the argument is that to meet "fleet" standards car manufacturers changed specs to 5W-20 in order to tweak fuel economy slightly higher for their line up. Fueling this theory was the fact that many vehicles went from specing 5w-30 one year to 5w-20 the next year with no change in engines.

 

[asker123]

Originally Posted By: AuthorEditor
Quote:
Also CAFE does not require 0-20 oils.

I think the argument is that to meet "fleet" standards car manufacturers changed specs to 5W-20 in order to tweak fuel economy slightly higher for their line up. Fueling this theory was the fact that many vehicles went from specing 5w-30 one year to 5w-20 the next year with no change in engines.


Not sure if this was a fact or not.
2002 Honda Accord LX has a 16 valve SOHC VTEC with a timing belt prescribed oil 5W30
2003 Honda Accord had 16 Valve DOHC iVTEC with a timing chain ( for the first time) - prescribed oil 5W20

Duel overhead Cam instead of Single overhead Cam and that Cam is driven by a chain ( which requires lubrication) instead of a belt. They increased horse power by 10 HP . IVTEC I dont know what it does but I guess it shifts Cam position which is also by oil pressure...

Seems like good reasons to go for a bit thinner oil than the previous engine... but All the above is my guess ( other than the engine type I mentioned) .. I am no expert..

 

[AuthorEditor]

Quote:
I think the argument is that to meet "fleet" standards car manufacturers changed specs to 5W-20 in order to tweak fuel economy slightly higher for their line up. Fueling this theory was the fact that many vehicles went from specing 5w-30 one year to 5w-20 the next year with no change in engines.


Quote:
Not sure if this was a fact or not.

Case in point were Crown Vics and the Mercury Grand Marquis. Used the same engine for many years and one year Ford changed their recommended lube to 5W-20 from 5W-30.