Motor Oil 5w/20 or 5w/30?

Built4.6 · July 5th, 2009, 04:07 PM

Just rebuilt my entire motor after 8 cracked rod bearings. 10:1 compression forged probe pistons (10.5cc dish), bored and honed stock shortblock, ported and polished PI heads, comp cams stage 2 cams.

I used 5w/20 Royal Purple before the rebuild, I was just wondering if I should step up to the 5w/30 Royal Purple? I've also heard of some guys running 10w/30 but that sounds to heavy. Some info. would be great. Price is not a question, I put the best in my car no sense in putting something cheap.

Let me know thanks

mpboy · July 5th, 2009, 04:08 PM

5w20

mpboy · July 5th, 2009, 04:09 PM

i use mobile1 full syn

but i have heard royal purp is goo0d shit too

and how the hell did you crack 8 rod bearings?

Ryguy33 · July 5th, 2009, 04:15 PM

also depends what the temp. is where you live

Built4.6 · July 5th, 2009, 04:17 PM

^ Man I punished that stock motor, I believe all of us on this forum know how shitty our stock pistons and rods are, I raced my boys Integra and after we finished the knocking was ridiculous and my motor just seized. Took it to the shop we cracked it open and all 8 were cracked! haha Crazy shit

Built4.6 · July 5th, 2009, 04:18 PM

Oh by the way the parts I mentioned on this post were what I did to it for the rebuild.
I cracked all 8 stock rod bearings.

Built4.6 · July 5th, 2009, 04:19 PM

Originally Posted by Ryguy33

also depends what the temp. is where you live

How so? I should go heavier for hotter areas?

Built4.6 · July 5th, 2009, 04:20 PM

Originally Posted by mpboy

i use mobile1 full syn

but i have heard royal purp is goo0d shit too

and how the hell did you crack 8 rod bearings?

ya i was using 5w/20 mobile1 when i first go the car then i made the switch after a friend of mine started using it on his '08 gt

mpboy · July 5th, 2009, 04:26 PM

Originally Posted by Built4.6

How so? I should go heavier for hotter areas?

yea if you live in really hot climates, thicker oil works a little better, but i live in SC and it gets in the 90's here and 5W20 is fine, if you live in AZ,NV,NM or something like that then the thicker oil will not lose its viscosity in hotter climates

Built4.6 · July 5th, 2009, 04:28 PM

Ya I live in NM dude, it can get pretty damn hot here. So the 5w/30 should be the best bet then?

What's this thing about some guys using 10W/30?

mpboy · July 5th, 2009, 04:39 PM

Multi-weight oils (such as 10W-30) are a new invention made possible by adding polymers to oil. The polymers allow the oil to have different weights at different temperatures. The first number indicates the viscosity of the oil at a cold temperature, while the second number indicates the viscosity at operating temperature

so a 10w-30, will be a little thicker when it is cold, than a 5w-20, and the mod motors have some tight clearances, but you live in NM so in the summer, 10w-30 will not hurt you at all

03SonicBoom · July 5th, 2009, 04:44 PM

Originally Posted by Built4.6

Ya I live in NM dude, it can get pretty damn hot here. So the 5w/30 should be the best bet then?

What's this thing about some guys using 10W/30?

Right now in NM there's not really going to be any difference between 5W30 and 10W30. The first number is the winter number for when it's cold. I've run 10W30 and 5W30 in my engine with no problems at all.

Built4.6 · July 5th, 2009, 04:52 PM

So overall with the set up I have with the rebuild 5w/30 would be best?
I'd rather stick with 5 rather than 10 for the viscosity since I've been using that since I first bought the car

UnixHH · July 5th, 2009, 06:55 PM

i like lucas syntheic oil stabalizer ..... 4qts mobile 1 full syn 5-20 1 qt lucas full syn.. keeps oil from dripping off all the surfaces and reduces harm during cold starts

UnixHH · July 5th, 2009, 06:57 PM

i would go with a 5-20 5-30 just means it has more friction modifiers in it. and they break down faster than the oil itself and reduces the effective life of the oil... my 2 cents

Built4.6 · July 5th, 2009, 07:21 PM

Never heard of mixing a stabilizer with a full synthetic oil, I know some drag dudes in town who do it but nothing on the street.

I think you're right about the dry starts though, with my rebuilt motor i can't have any of that. 4 quarts 5w/20 RP with 1 quart stabilizer should do the trick? So you add the stabilizer for 5 quarts total for every oil change?

UnixHH · July 5th, 2009, 07:22 PM

yup 5qt total

03SonicBoom · July 5th, 2009, 07:24 PM

Originally Posted by UnixHH

yup 5qt total

You only run 5 quarts of oil/stabilizer? The manual calls for 6 quarts.

UnixHH · July 5th, 2009, 07:27 PM

saleen calls for 5qts +/_ .25 qts

Built4.6 · July 5th, 2009, 07:29 PM

^Damn didn't realize you had an SC Saleen. So I'm going to need 5 quarts RP and 1 qt stabilizer?

July 5th, 2009, 04:07 PM	#1
Built4.6 Banned 2001 Mustang GT N/A Join Date: Jul 2009 Location: Las Cruces, NM Posts: 15 iTrader: 0 reviews	Motor Oil 5w/20 or 5w/30? Just rebuilt my entire motor after 8 cracked rod bearings. 10:1 compression forged probe pistons (10.5cc dish), bored and honed stock shortblock, ported and polished PI heads, comp cams stage 2 cams. I used 5w/20 Royal Purple before the rebuild, I was just wondering if I should step up to the 5w/30 Royal Purple? I've also heard of some guys running 10w/30 but that sounds to heavy. Some info. would be great. Price is not a question, I put the best in my car no sense in putting something cheap. Let me know thanks

July 5th, 2009, 04:15 PM	#4
Ryguy33 Hardcore Enthusiast 2002 Mustang Gt 3 seconds......flat Join Date: Jan 2009 Location: L.A. , California Posts: 1,933 iTrader: 1 reviews	also depends what the temp. is where you live __________________ Mods = stuff to make me take corner faster

July 5th, 2009, 06:55 PM	#14
UnixHH MM Fanatic 2003 Saleen S281 Join Date: Nov 2008 Location: Houston, Tx Posts: 4,274 iTrader: 0 reviews	i like lucas syntheic oil stabalizer ..... 4qts mobile 1 full syn 5-20 1 qt lucas full syn.. keeps oil from dripping off all the surfaces and reduces harm during cold starts __________________ 480RWHP 450RWTQ 15psi @ 15* on 91 octane

July 5th, 2009, 06:57 PM	#15
UnixHH MM Fanatic 2003 Saleen S281 Join Date: Nov 2008 Location: Houston, Tx Posts: 4,274 iTrader: 0 reviews	i would go with a 5-20 5-30 just means it has more friction modifiers in it. and they break down faster than the oil itself and reduces the effective life of the oil... my 2 cents __________________ 480RWHP 450RWTQ 15psi @ 15* on 91 octane

July 5th, 2009, 07:21 PM	#16
Built4.6 Banned 2001 Mustang GT N/A Join Date: Jul 2009 Location: Las Cruces, NM Posts: 15 iTrader: 0 reviews	Never heard of mixing a stabilizer with a full synthetic oil, I know some drag dudes in town who do it but nothing on the street. I think you're right about the dry starts though, with my rebuilt motor i can't have any of that. 4 quarts 5w/20 RP with 1 quart stabilizer should do the trick? So you add the stabilizer for 5 quarts total for every oil change? __________________ Basic Mods: Bassani Catted X-Pipe Magnaflow Catback JLT CAI MGW Short Throw Shifter 1.5" Eibach Sportline Springs FRPP 4.10's FRPP Alum. Driveshaft *4.6l Rebuild in Garage

July 5th, 2009, 04:17 PM	#5
Built4.6 Banned 2001 Mustang GT N/A Join Date: Jul 2009 Location: Las Cruces, NM Posts: 15 iTrader: 0 reviews	^ Man I punished that stock motor, I believe all of us on this forum know how shitty our stock pistons and rods are, I raced my boys Integra and after we finished the knocking was ridiculous and my motor just seized. Took it to the shop we cracked it open and all 8 were cracked! haha Crazy shit

July 5th, 2009, 04:18 PM	#6
Built4.6 Banned 2001 Mustang GT N/A Join Date: Jul 2009 Location: Las Cruces, NM Posts: 15 iTrader: 0 reviews	Oh by the way the parts I mentioned on this post were what I did to it for the rebuild. I cracked all 8 stock rod bearings.

July 5th, 2009, 04:28 PM	#10
Built4.6 Banned 2001 Mustang GT N/A Join Date: Jul 2009 Location: Las Cruces, NM Posts: 15 iTrader: 0 reviews	Ya I live in NM dude, it can get pretty damn hot here. So the 5w/30 should be the best bet then? What's this thing about some guys using 10W/30?

July 5th, 2009, 04:52 PM	#13
Built4.6 Banned 2001 Mustang GT N/A Join Date: Jul 2009 Location: Las Cruces, NM Posts: 15 iTrader: 0 reviews	So overall with the set up I have with the rebuild 5w/30 would be best? I'd rather stick with 5 rather than 10 for the viscosity since I've been using that since I first bought the car

July 5th, 2009, 07:22 PM	#17
UnixHH MM Fanatic 2003 Saleen S281 Join Date: Nov 2008 Location: Houston, Tx Posts: 4,274 iTrader: 0 reviews	yup 5qt total __________________ 480RWHP 450RWTQ 15psi @ 15* on 91 octane

July 5th, 2009, 07:27 PM	#19
UnixHH MM Fanatic 2003 Saleen S281 Join Date: Nov 2008 Location: Houston, Tx Posts: 4,274 iTrader: 0 reviews	saleen calls for 5qts +/_ .25 qts __________________ 480RWHP 450RWTQ 15psi @ 15* on 91 octane

July 5th, 2009, 07:29 PM	#20
Built4.6 Banned 2001 Mustang GT N/A Join Date: Jul 2009 Location: Las Cruces, NM Posts: 15 iTrader: 0 reviews	^Damn didn't realize you had an SC Saleen. So I'm going to need 5 quarts RP and 1 qt stabilizer? __________________ Basic Mods: Bassani Catted X-Pipe Magnaflow Catback JLT CAI MGW Short Throw Shifter 1.5" Eibach Sportline Springs FRPP 4.10's FRPP Alum. Driveshaft *4.6l Rebuild in Garage

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