Recent Topics
2002 Tacoma 3.4L 5VZFE | M1 5W40 TDT |9,764 Miles
by madibob
12/17/14 04:48 PM
4 Ball Test...
by 1bioguy
12/17/14 04:26 PM
Bought a used truck. Oil recommendation :)
by 2012AccentSE
12/17/14 03:06 PM
Which oil would you choose?
by Noobie
12/17/14 03:03 PM
what are the different names for a tow truck?
by Vikas
12/17/14 02:50 PM
2004 Expedition trans fluid and diff oil
by Thebuckaman
12/17/14 02:48 PM
Big News!! The chicken is safe!
by andrewg
12/17/14 02:40 PM
Snap-On stud remover with 3 collets
by flanso
12/17/14 02:27 PM
Issues with this site and IE
by Oldswagon
12/17/14 02:07 PM
Wheel Bearing Diagnosis
by Oldswagon
12/17/14 02:05 PM
Sweet smelling oil...additive?
by Plumber
12/17/14 12:55 PM
Southern Air 747 emegency over Qatar
by KD0AXS
12/17/14 12:49 PM
Newest Members
studmann04, Damspele, milspec1, GreaserGary, DAKOTAKIDD
52199 Registered Users
Who's Online
93 registered (01rangerxl, 2oldtommy, 2010_FX4, aa1986, 1bioguy, 1foxracing, 10 invisible), 1507 Guests and 184 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
52199 Members
66 Forums
223567 Topics
3544502 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Page 2 of 2 < 1 2
Topic Options
#3448801 - 08/07/14 12:02 PM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: that_guy318]
KCJeep Offline


Registered: 06/30/11
Posts: 4731
Loc: Mahzurrah!
Blue bottle STP does have zinc, but less than the motor oil you are adding it to. It is primarily an oil thickener. I still have a soft spot for it though. No oil change was complete without a can of STP when I was a teen. Have used it in the Jeep fairly recently and it did seem to like it, the Jeep does favor thicker oils though.

Great UOA I wouldn't change a thing it's obviously working for you.
_________________________
2004 Jeep GC WJ 4.0 @ 123k Pennzoil YB 5w30 - MoS2
Napa Silver 31516
KIA Sedona 41k, Chevy Lumina 174k, Chrysler Sebring 172k, Chrysler Concorde 97k

Top
#3449215 - 08/07/14 08:15 PM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: that_guy318]
that_guy318 Offline


Registered: 08/04/14
Posts: 12
Loc: PA and SC
I think my engine likes the thicker oil too. I have right under 40lbs of pressure at idle and right under 60 or so at cruising speed.
_________________________
-99 Durango 5.2L V8 168k miles
Castrol GTX High Mileage 10w30 with Purolator/Mopar filter every ~3,500 miles

Top
#3449401 - 08/08/14 02:47 AM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: that_guy318]
Garak Offline


Registered: 12/05/09
Posts: 11782
Loc: Regina, Saskatchewan, Canada
Originally Posted By: that_guy318
Yeah, it seems like the stp is working. I'm kind of surprised that there wasn't more zinc showing up on the report though. I'm going to keep using it though, it's worked for years, so why change it.

Somewhere in the VOA section, I did the calculations to show that regular STP will actually dilute the zinc content of most motor oils. It's worse than useless as a ZDDP additive.
_________________________
Plain, simple Garak.

2008 Infiniti G37 coupe - Mobil Delvac 1 ESP 5w-40, Hastings LF113
1984 F-150 4.9L six - Quaker State GB 10w-30, Wix 51515

Top
#3451974 - 08/10/14 09:42 PM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: Garak]
that_guy318 Offline


Registered: 08/04/14
Posts: 12
Loc: PA and SC
Originally Posted By: Garak
Originally Posted By: that_guy318
Yeah, it seems like the stp is working. I'm kind of surprised that there wasn't more zinc showing up on the report though. I'm going to keep using it though, it's worked for years, so why change it.

Somewhere in the VOA section, I did the calculations to show that regular STP will actually dilute the zinc content of most motor oils. It's worse than useless as a ZDDP additive.


It looks like it increased the zinc content of my oil though. http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1414695
_________________________
-99 Durango 5.2L V8 168k miles
Castrol GTX High Mileage 10w30 with Purolator/Mopar filter every ~3,500 miles

Top
#3452063 - 08/11/14 01:31 AM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: that_guy318]
Garak Offline


Registered: 12/05/09
Posts: 11782
Loc: Regina, Saskatchewan, Canada
Perhaps, if the original ZDDP content was low enough, of course. For most oils, it's certainly not true.
_________________________
Plain, simple Garak.

2008 Infiniti G37 coupe - Mobil Delvac 1 ESP 5w-40, Hastings LF113
1984 F-150 4.9L six - Quaker State GB 10w-30, Wix 51515

Top
#3457997 - 08/17/14 01:16 PM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: that_guy318]
2KBMW Offline


Registered: 10/29/03
Posts: 476
Loc: Ontario Canada
[quote=that_guy318]Yeah, it seems like the stp is working. I'm kind of surprised that there wasn't more zinc showing up on the report though. I'm going to keep using it though, it's worked for years, so why change it.

I'm also surprised that the viscosity was that low or stayed in the 30 weight range. I thought that STP raised the viscosity by two grades ie. a 30 weight oil would turn into a 50 weight. The report said it was a 40 weight though so do you think there was an error made ?

Top
#3458355 - 08/18/14 12:14 AM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: 2KBMW]
that_guy318 Offline


Registered: 08/04/14
Posts: 12
Loc: PA and SC
Originally Posted By: 2KBMW


I'm also surprised that the viscosity was that low or stayed in the 30 weight range. I thought that STP raised the viscosity by two grades ie. a 30 weight oil would turn into a 50 weight. The report said it was a 40 weight though so do you think there was an error made ?


I really don't know enough about this to say one way or the other.
_________________________
-99 Durango 5.2L V8 168k miles
Castrol GTX High Mileage 10w30 with Purolator/Mopar filter every ~3,500 miles

Top
#3459086 - 08/18/14 09:03 PM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: 2KBMW]
artificialist Offline


Registered: 09/23/07
Posts: 7022
Loc: Florida
Originally Posted By: 2KBMW
[quote=that_guy318]Yeah, it seems like the stp is working. I'm kind of surprised that there wasn't more zinc showing up on the report though. I'm going to keep using it though, it's worked for years, so why change it.

I'm also surprised that the viscosity was that low or stayed in the 30 weight range. I thought that STP raised the viscosity by two grades ie. a 30 weight oil would turn into a 50 weight. The report said it was a 40 weight though so do you think there was an error made ?

Well, what ratio of STP to 10w30 engine oil? If the sump is big, the thickening effect of 1 bottle of STP might not be very big.

The second thing to consider is oil shear. How much did the 10w30 oil shear, and how much did the STP shear? Enough shearing, and an oil will go down a viscosity grade, making a 10w40 into a 10w30 and so on.

My dad told me that in the 1960s, guys used STP because they thought it was the cool thing to do. Back then, it may have made sense, due to the limited detergent content of 1960s engine oil, and because not all oils had high ZDDP.
_________________________
2010 Lancer Ralliart Sportback

Top
#3470772 - 09/01/14 11:18 AM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: artificialist]
that_guy318 Offline


Registered: 08/04/14
Posts: 12
Loc: PA and SC
Originally Posted By: artificialist
Originally Posted By: 2KBMW
[quote=that_guy318]Yeah, it seems like the stp is working. I'm kind of surprised that there wasn't more zinc showing up on the report though. I'm going to keep using it though, it's worked for years, so why change it.

I'm also surprised that the viscosity was that low or stayed in the 30 weight range. I thought that STP raised the viscosity by two grades ie. a 30 weight oil would turn into a 50 weight. The report said it was a 40 weight though so do you think there was an error made ?

Well, what ratio of STP to 10w30 engine oil? If the sump is big, the thickening effect of 1 bottle of STP might not be very big.

The second thing to consider is oil shear. How much did the 10w30 oil shear, and how much did the STP shear? Enough shearing, and an oil will go down a viscosity grade, making a 10w40 into a 10w30 and so on.

My dad told me that in the 1960s, guys used STP because they thought it was the cool thing to do. Back then, it may have made sense, due to the limited detergent content of 1960s engine oil, and because not all oils had high ZDDP.


About 4.5 quarts of oil and 1 bottle (I think it's about a pint) of stp.
_________________________
-99 Durango 5.2L V8 168k miles
Castrol GTX High Mileage 10w30 with Purolator/Mopar filter every ~3,500 miles

Top
#3526082 - 10/31/14 12:45 PM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: that_guy318]
84zmyfavorite Offline


Registered: 07/14/10
Posts: 675
Loc: Wenatchee, W.A.
Both my 1985 Jeep Grand Wagoneers 360 and my 1993 Jeep Grand Cherokees 5.2Liter 318 recieved a bottle of STP Blue bottle at their last oil change. Glad to see others having good results with it as well. I wear my STP Teeshirt when changing oil as well!

Top
#3534478 - 11/10/14 09:11 AM Re: Castrol GTX HM 10w30 +STP/3,300mi/99 Durango 5.2 [Re: 84zmyfavorite]
that_guy318 Offline


Registered: 08/04/14
Posts: 12
Loc: PA and SC
Sounds like I need to get one of those shirts
_________________________
-99 Durango 5.2L V8 168k miles
Castrol GTX High Mileage 10w30 with Purolator/Mopar filter every ~3,500 miles

Top
Page 2 of 2 < 1 2