GMC 4.3 dino oil for 5K changes

Messages
394
Location
Ky
IM going to have to make a decision soon. Im down to Mobile 5000 or what ever they call it now, PYB, or Motorcraft. It takes 5w 30. PYB and Motorcraft are about the same price in my area and the Mobile is a bit cheaper. I still use the AC delco PF 52 filters that are pretty cheap. I have read that the 4.3 engine is pretty easy on oil. The current fill is Mobile 5K and Im about 1K miles from the 5K change. I hope I have not pushed it too far. What do you think? Bear in mind sometimes I get really busy and could go over the 5K by 500 miles. I just cant stomach the high priced synthetics on this old truck any longer. Am I right in thinking that the PYB or Motorcraft is a bit better oil and will take the higher mileage a bit better? IM no guru and try to understand what I read.
 
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Messages
695
Location
Manvel, Texas
Any should be fine. PYB is readily available and the 4.3 seems to "like" it. Motorcraft is a good readily available blend if running a blend makes you feel better. I have considered running PYB in my 4.3 as I have talked to several people with this engine that use it and liked the results. One of the benefits of the 4.3 is that it's a SBC. Which means its a cast iron, 20+ year old design that's virtually bullet proof. If you change the oil regularly your lavishing more care on this motor than many of them have seen.
 
Messages
488
Location
Detroit, Michigan
Driving conditions and weather are great factors in oil change intervals. My grocery getter, '06 Sentra that see's only stop light to stop light driving - OCI's every 3 months with synthetic. Our special occasion car,'06 Maxima gets OCI's once a year in the Fall before it is stored. My work car, '00 Suzuki gets OCI's every 4K miles which is about 60 days of all Freeway use. Personally if the GMC was my truck I would go 4K miles or 3 months with any mineral oil...my preference would be Castrol GTX 5W30 in the box with a Purolator filter. Of course that is my recommendation. I think 5K with the Mobil would lead to high Total Acid Numbers.
 

JRed

Site Donor 2021
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2,311
Location
Virginia
The 4.3 will remain lubricated on peanut butter, I think, so oil choice isn't an issue. Use the cheapest name-brand dino you can find. If the truck sees light duty 5k should be fine. I've got a post on here about a 4.3 that hadn't had an oil change in two years and saw what most of us would consider "super duper severe" service. Transmission died @ 40k, engine still ran like a champ.
 

nomochevys

Thread starter
Messages
394
Location
Ky
My driving is so mixed I cant put my finger on it. I understand your point perfectly. I keep this in the back of my mind all of the time. 4k should be safe no doubt but with high gas and oil prices Im trying to get the most bang for the buck. I felt like 5K should be a safe place to change oil out. I dont want to waste good oil. I would have never considered this years ago but the rotten economy has made me cut back and stretch things as far as possible now.
 

nomochevys

Thread starter
Messages
394
Location
Ky
Originally Posted By: JRed
The 4.3 will remain lubricated on peanut butter, I think, so oil choice isn't an issue. Use the cheapest name-brand dino you can find. If the truck sees light duty 5k should be fine. I've got a post on here about a 4.3 that hadn't had an oil change in two years and saw what most of us would consider "super duper severe" service. Transmission died @ 40k, engine still ran like a champ.
\\\ Ok, IM probably going to stick with MObile 5K or super or what ever they call it now. I just dont want to push it too far. I know Motorcraft and Pennzoil is good stuff but its quite a bit higher. Price really matters in this case. I kinda feel like Im on the edge at 5K with it.. Edit: The truck is light duty. Seldom tows and even then its only a lawnmower or something small. No more big boats like it used to do. Most of the time its empty.
 
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Messages
695
Location
Manvel, Texas
You have made a reasonable decision. Again, the 4.3 is one tough mother... many see severe fleet use and neglect and just shrug it off. 5K OCIs with a quality dino and filter will see that motor last longer than your desire to keep the truck in all likelihood.
 

nomochevys

Thread starter
Messages
394
Location
Ky
Originally Posted By: apwillard1986
You have made a reasonable decision. Again, the 4.3 is one tough mother... many see severe fleet use and neglect and just shrug it off. 5K OCIs with a quality dino and filter will see that motor last longer than your desire to keep the truck in all likelihood.
I hope mobile super or 5k is considered a quality dino oil. The 4.3 does have a good reputation on durability but its down and power and thirsty compared to what we have now. We have so much better stuff now. I remember back when it was considered powerful. LOL
 
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18,616
Location
Michigan
Originally Posted By: JRed
The 4.3 will remain lubricated on peanut butter, I think, so oil choice isn't an issue. Use the cheapest name-brand dino you can find. If the truck sees light duty 5k should be fine. I've got a post on here about a 4.3 that hadn't had an oil change in two years and saw what most of us would consider "super duper severe" service. Transmission died @ 40k, engine still ran like a champ.
+1
 
Messages
285
Location
Vancouver, BC
No scientific proof off course, but at least I perceived a significant difference in how my 4.3 runs since I changed to more expensive oil. For several years I ran it on nothing but Castrol GTX, but since the van is used a lot for towing a 3500 lb trailer, I decided to use HD oil. For the last 4 oil changes, 2 have been on Rotella T6 syn, and 2 have been on Delo 400LE syn. It seems to run like in butter. I know that the oil costs you more to buy, but you don't have to extend your oci's all that much before you are breaking even, or even saving money - imo.
 

JDD

Messages
595
Location
Utah
Originally Posted By: JRed
The 4.3 will remain lubricated on peanut butter,
Do you know if Jiffy or Skippy (I'm assuming creamy) makes a syn and what percentage is GRP III, IV, or V? I've heard the PB GRP 4s have solubility issues and you have to stir them first--
 

JDD

Messages
595
Location
Utah
Motorcraft in a Chevy? Are you looking for bad karma? That being said, the syn blend motorcraft WAS the best buy IMO for about 2 years until the major price hike. Factory fill on a lot of Fords and Mazdas.
 

JDD

Messages
595
Location
Utah
" One of the benefits of the 4.3 is that it's a SBC. Which means its a cast iron, 20+ year old design that's virtually bullet proof." This family of engines referenced above is the high water mark in the small block world. Maybe not all the other bits on the trucks can the same be said about, but the 4.3 / 5.7 will go and go. It doesn't matter IMO what oil you run, but check the oil regularly. Dirty oil is infinitely better than no oil. If it makes you feel better, go with the one with '5000' written on the front, since you want to go 5000 mi. I'm sure XOM has engineered a buffer in there as well, so going over is not going to blow up your engine. Realistically, your choices are all very good. Remember XOM does provide high quality basestocks to a lot of different mfgrs and has a little experience in the business. Hard to buy a bad SN or SM oil from them.
 
Messages
722
Location
Kansas City, MO
If price/value is your primary concern, then Mobil Super 5k or QSGB are probably your best bets. When I checked last month, Wal-Marts near my house had jugs of the Mobil for less than $15, and jugs of QSGB for less than $13. Unless your use is extremely severe, meaning tons of short trips and almost no trips long enough for the oil to get up to operating temp, either of those with a decent filter should be OK for your 5k OCI. As others have said, that engine is rock-solid.
 
Messages
1,429
Location
Missouri
Originally Posted By: bigdawg74
Originally Posted By: JDD
Motorcraft in a Chevy? Are you looking for bad karma?
I wouldn't even put Motorcraft oil in the bed of my Chevy... no-no
My 99 k1500 ran 180k miles on motorcraft oil. Only problem was the notorious vortec intake gasket. I liked the oil so much i bought a ford, wait make that 2 fords now lol. Personally i would run the conventional quakerstate but if you have had no problems with consumption or noise using mobil theres no reason to quit what has been working.
 
Messages
1,271
Location
Dallas Texas
Originally Posted By: apwillard1986
You have made a reasonable decision. Again, the 4.3 is one tough mother... many see severe fleet use and neglect and just shrug it off. 5K OCIs with a quality dino and filter will see that motor last longer than your desire to keep the truck in all likelihood.
The "W" VIN (with VORTEC badging, 1993 and later) moreso than even the "Z" VIN! But yeah, that "W" VIN even has an "octane sensor" that means it adjusts to run even better of 93-octane gas!!!!!!! Hmmm. 5W-30 or 5W-40, heck even 0W for this engine with the new oil and it will like it. smile (It IS A small block short two cylinders.)
 
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