oil viscosity ?'s - Honda Prelude Forum

jsmooney · 07-20-2003, 01:33 PM

the s and the si use 5w30, but the vtec uses 10w30, right?

can someone explain the difference between 5w30 and 5w20? i just saw it on a website.....

http://www.mobil.com/USA-English/Lub...Clean_Oils.asp

jsmooney · 07-20-2003, 01:35 PM

is the viscosity really that much of a difference?

brendon2k · 07-20-2003, 06:18 PM

its a measured things so there is a difference but it is not huge like you will ruin your engine putting in ove instead of the other.

DanYO · 07-20-2003, 08:10 PM

the first number is the characteristic weight of the oil when the engine and oil are still cold, 5 weight.

when the engine and oil heat up, the oil viscosity chagnes to the second number ---- 30 or 20 weight.

lighter oil lubricates better when cold, however at higher temperatures, the viscosity decreases and so does lubrication. that's why you want a heavier oil when the operating temps are higher. heavier oils lubricate better than lighter oils at higher temperatures.

AccordSleeper · 07-21-2003, 06:33 AM

5w-20 is purely for hondas benefit so they can have better fuel efficieny. that stuff is like water though and i don't like it.

the VTEC ludes 93-96 require 10w-30 cause of their closed deck design doesn't have good cooling properties like open deck.
i use 10w-30 summer, 5w-30 winter in mine..of course mobil1 too.

nemicron1 · 07-21-2003, 06:51 AM

h23's(si) are closed deck as well, not sure about f series but would assume so. What benefit would having 5 more weight have on start up i.e. 5w30 vs. 10w30(not weather-related). It would seem recommendations for all engines(within the same family) should be the same.

AccordSleeper · 07-21-2003, 02:22 PM

f series are open deck, that's just an accord motor.

the thinner weight means the oil pump can get it flowing quicker which means oil gets through the motor faster. the thing is when it's above 30 degrees or so this not an issue. especially when it's 90+ degrees in stop and go traffic with a closed deck, i'd rather have 10w-30.

i believe another reason for 10w-30 is cause VTEC works on oil pressure and 10w-30 makes it engage better. although i notice no difference with 5w-30 or 10w-30. it's just that in NH it gets way too cold for 10w-30 so 5w-30 is a must.

jsmooney · 07-21-2003, 02:39 PM

what's the difference between closed and open decks? the f22 block is slightly different but it has the same head as the h23

prelude styl · 07-21-2003, 03:32 PM

Hes talking about the F22A1, not the JDM F22.

jsmooney · 07-22-2003, 01:40 AM

okay, oops on my part!

AccordSleeper · 07-22-2003, 06:28 AM

Quote:

Originally posted by UBetterBelieveIt
okay, oops on my part!

yeah, didn't notice the f22b in your sig

jsmooney · 07-22-2003, 01:15 PM

it's okay, i understand more now. I just wasnt sure what the second number was. What would 5w20 do in the car? would it be "better" or anything?