What's the difference between 5W-20 and 5W-30?

[Jiggaboojeff]

Hello guys my oil is almost due and I was wondering which Oil I should use My manual says 5W-20 but alot of people recommend I should use 5W-30 Mobil 1 Synthetic or Pennzoil Ultra/Platinum. What is the difference? Also I just need help deciding which oil is best for the car, life and performance wise. THANKS!!!!

[ep3demon]

dont listen to them your engine clearences specify 5w-20

the numbers signify the viscosity of the a multiviscosity oil wich means that it has a thinness of 5 and the w stands for winter not weight. oil is measured by its volume ie liters/pints. wich means when the oil is cold it will be at the 5 viscosity
after the oil is warmed up the viscosity will change to the thickness of the second number. your engine clearences are nice and tight in these newer cars wich results in less blowby and other things. unless your car severely worn out and and your clearences have increased there really is no need for you to switch.

[Jiggaboojeff]

Should I just use Regular or Synthetic 5W-20? I live in California, The Bay area so the weather is bipolar haha. What kind of oil and brand do you recommend?

[02TWSI]

I use 5-30. I don't think anyone on this board still uses the 5-20 recommended.

[talonXracer]

5w20 will lead to a short engine life guaranteed !!!

The local stealerships had alot of complaints for engine noise and abnormal wear with the 5w20 swill. They changed to recommending only 5w30 and their complaints and warranty claims dropped to nill.

Even Honda stated the K20A3 was speced for the 5w20 swill to attain LEV status and lower the fleet average, that costs less for them in tarriffs and fines vrs replacing engines and dealing with complaints.

Only use 5w20 swill if you enjoy engine noise and destroying the engine! There is a reason why the rest of the K's have 5w30 specd.


Supposedly there are some 5w20's that are supposed to be as good as a 30 weight, but I have yet to see any real world corroboration of those claims.

[Deadphishy]

dont listen to them your engine clearences specify 5w-20

the numbers signify the viscosity of the a multiviscosity oil wich means that it has a thinness of 5 and the w stands for winter not weight. oil is measured by its volume ie liters/pints. wich means when the oil is cold it will be at the 5 viscosity
after the oil is warmed up the viscosity will change to the thickness of the second number. your engine clearences are nice and tight in these newer cars wich results in less blowby and other things. unless your car severely worn out and and your clearences have increased there really is no need for you to switch.


There is Zero difference in "spec" between the clearances of a k20a3 and a k20a2. Yet the A3 uses thinner Oil? Fleet economy is 100% the reason for a 20 grade.

If you are worried about the Oil then use a Synthetic 5w30. They are thinner at start up then Dyno Oil.
If you really want to run a 5w20, I would run one that has a very high zinc and prosperous count. This will improve film strength.
Ultra/plat is a really nice, easy to find oil. The more UOI (used oil analysis) i see the more I think they are on top of the mainstream market.

[introvert]

I've always went 5-30 synthetic. Decided to try 5-20 this recent change.. Do notice more engine noise when cold, but it seems quieter once idle and warmed up. It's only been a couple hundred miles, acceleration seems semi improved but that could just be a placebo effect. Fuel economy seems better.. But I'll have to wait and see. I'll definitely be going back to 5-30, though.

[Jiggaboojeff]

5-30 Pennzoil ultra synthetic is what I'm going to use for the next 3 oil change too see the result.

[Distance]

this is irrelevant to what the op asked but i used mobile1 5-30 for the winter and 5-40 amsoil for the summer.

[oneglory]

5w20 =

http://i3.photobucket.com/albums/y84/oneglory/car%20stuff/IMGP3867.jpg

[sippyyy]

There is Zero difference in "spec" between the clearances of a k20a3 and a k20a2. Yet the A3 uses thinner Oil? Fleet economy is 100% the reason for a 20 grade.

Stock allowed rod to crank bearing clearance:
K20A3 (Base RSX engine) 0.0008-0.0020 inch
K20A2 (RSX type S) 0.0013 - 0.0024 inch

Max service limit:
K20A3 (Base RSX engine) 0.0024 inch
K20A2 (RSX type S) 0.0028 inch

[McTaggart34]

Full synthetic Royal Purple 5-30 with lucas oil added.

[galognu]

Have not been here in a long time. My EP Hatch now has 189K. I think I took over it with 90K, and have faithfully been using the recommended 5w-20. In the last 8 months I have had to make routine long trips because of work, and have noted that I am burning about a quart just shy of a 1000 miles. I've used every additive there is, including high milage oil, but no change.

As an aside, I had been getting about 25mpg till I heard a squeal, and on changing my brakes realized my calipers were pretty bad off. I changed all 4 calipers and milage jumped to 28-29 consistently.

I do not baby this car. I drive the piss out of it routinely. Highway 80-95 when I can get away with it.

Looks like I will have to keep it for at least another year. Besides what I read here about the 5w-30, any other suggestions.

The autozone guy told me if if smokes under load its the rings, if it smokes going downhill under vacuum its the valves. If I gun it hard, I can see smoke with the car sitting there, but I never notice smoke when I am driving hard.

Is it worth having the valves checked? and if need adjustment how much??

Thanks

[rhdsirek4]

Full synthetic Royal Purple 5-30 with lucas oil added.

I agree

[ninebreaker8]

using 5 20 will lead to cam galling, as stated by OneGlory for those of you who may not know what the picture represents

[AceEngineer]

I gotta tell all you guys what a help this thread has been to me. My 02 EP3 has had a lifelong (132k) diet of Mobile1 5-W20 per the owners manual and lately I have been using their Extended Life varity, changing it every 5000 mi. I have an oil change scheduled this weekend and this time I bought 5-W30 based on this thread. Just a couple of weeks ago I did a solo (just me & my EP3) NM to MA to NC and back to NM loop of the country and put well over 6000 highway mi on it in a continuous trip. I burned 1 quart of oil, put in about 500 mi from home on the return. Not sure if it burned the whole quart, the front seal weeps a bit but doesn't leave a drop in my drive yet. I am making the tool to hold the front serpentine sprocket so I can replace the front seal.
Just wanted to say thanks for all the good info in this thread.

AceEngineer

[1fasthb]

So I never really cared about oil so I came here and I see this and been using 5w20 for like 10 years in my car but only have 60k miles is it to late for me to change to 5w30? And what's the best oil to get in this weight royal purple or something else? Also my head does make some louds noises tho prolly galling alote but I never rem the car always shifting at like 3k but anyways thanks for any advice