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Do you run all conventional or synthetic oil in the k5?

wazzabie said:
Do you run all conventional or synthetic oil in the k5?
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I will say this, if you don't drive it much and you do less than 5-6k a year, you can justify the synthetic, but when the truck was built it was spec'd with conventional oil, so that works just fine.
My cars only use synthetic if they are occasional use everything else gets changed often with a reputable conventional oil.
My preference has been Castrol magnatec
 
I've just ran conventional oil by whichever brand is cheaper at the time for years and years now. Mainly just try to get the weight recommend by the car manufacturer, but I have mixed weights of oil before....as mentioned above it's a lot better to put a little 15W-40 in an engine that normally runs 5W-30 versus running it low! Have never had an engine issue on a vehicle just using the philosphy to keep the oil changed at a reasonable interval and use the correct weight. If the vehicle is equipped I almost always just go by the oil life indicator. Here are the older high mileage vehicles I've had with no engine issues:
2003 2500HD 6.0L - bought new and now has 150,000+ miles
2007 Honda Odyssey - had 130,000+ on it when we traded it in
2003 Hyundai Elantra - got it with 80,000 miles and gave it away at 180,000 miles 2 years ago, car is still running
1990 K5 w/ 6.2L - got it in 1994 with 49,000 miles, now has 120,000 miles
 
6.2Blazer said:
I've just ran conventional oil by whichever brand is cheaper at the time for years and years now. Mainly just try to get the weight recommend by the car manufacturer, but I have mixed weights of oil before....as mentioned above it's a lot better to put a little 15W-40 in an engine that normally runs 5W-30 versus running it low! Have never had an engine issue on a vehicle just using the philosphy to keep the oil changed at a reasonable interval and use the correct weight. If the vehicle is equipped I almost always just go by the oil life indicator. Here are the older high mileage vehicles I've had with no engine issues:
2003 2500HD 6.0L - bought new and now has 150,000+ miles
2007 Honda Odyssey - had 130,000+ on it when we traded it in
2003 Hyundai Elantra - got it with 80,000 miles and gave it away at 180,000 miles 2 years ago, car is still running
1990 K5 w/ 6.2L - got it in 1994 with 49,000 miles, now has 120,000 miles
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Yeah my 2003 Honda civic bought new, never had synthetic in it always changed @10k and at 70k had the atf changed to generic mercon lll and changed every 40k instead of recommended 90k.
Has 255k now still all original and did a compression test and I have 205-215psi between all of the cylinders.
I think the engine is still going well :dunno:
 
Yeah, 398k on my 97 Ranger, regular old Oil. Every 5-7K
Same for the 74K5.
Unless it calls for it like the F150 semi synthetic.
 
wazzabie said:
I have many cases of old conventional motor oil that I would like to use.
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Use them up!

It's a question of what you're trying to do. I run Mobil 1 in my new engines to give them a chance at long life, and Walmart Supertech conventional in my Blazer which has a mostly-worn-out engine.

If you're already running a high-mileage and have ring/bearing wear, the difference between dinosaur bones and synthetic isn't going to matter much. Just run the correct viscosity and keep it clean by changing it frequently enough.
 
wazzabie said:
I have many cases of old conventional motor oil that I would like to use.
Click to expand...

For what its worth, I'm not seeing anyone (manufacturer, articles, etc) that recommends over 5 years of shelf life for oil. Even synthetic, straight from Mobil. Can't recall how I stumbled upon that info, but it somewhat surprised me.

DexMerc from Warren, they also told me five years.

Not saying that to be a nanny...some of us like to hoard oil when it's cheap, but theoretically, when performance matters, it is probably not the best idea to store and use old oil. Mines just over 6 years, haven't seen any warning signs that it's "bad", but I doubt when stored halfway decently, an extra year is going to show evidence of starting to change.
 
mrk5 said:
Synthetic, Amsoil Zrod with the zinc additives.
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I run Amsoil also, container says "contains zinc" but it is not the "Zrod" that you are referring to. I am wondering if I should switch. I have a 1978 small block 400. I using Amsoil 20W-50. Original spec called for "SAE 30".
 
I like certain oils because they don't fall apart and keep crap in suspension better.

I like synthetic oils because they hold up better to heat. Most synthetic oils are actually dinosaur oils anyway. Otherwise, regular old general population dinosaur oils are fine.

I think just about any name brand oil today is so good it doesn't matter much. Certain ones I stay away from because they don't seem to handle heat well (regular Pennzoil, regular Quaker State, regular Valvoline).

I tend to use Mobil1 for engine oil in anything that sees a lot of heat (air cooled power equipment, abused cars) and anything that sees a lot of dirty operation I use diesel oil (usually Rotella or Delvac).

Recently I have been trying to break in a full-roller Cadillac 500. I have about 3 hours of runtime on it now and 400 miles and I still have blowby and barely get any sparklies in the oil. Have changed the oil 4 times trying to find a crappy enough oil to allow the motor to break in. Funny thing... Shell Formula or whatever it is called 10w40 at $2/quart seems to be working. Even the farm store garbage was too slippery. Bore inspection camera shows no evidence of the motor breaking in. Funny story... put Mobil1 5w30 in it and the engine RPM went up 200rpm at idle. It actually does run cooler with a decent synthetic in it (use infrared thermometer on everything including the engine oil cooler which is actually a 19 row Derale stacked plate transmission cooler).
 
I've read that adding a quart of synthetic to regular oil provides 80% of the added protection and advantages of a full crankcase of synthetic..

This may be why "semi-synthetics" are popular,and older high mile engines would likely tolerate the addition of only one quart vs a full load of it better..
 
i broke the 4.3 v-6(roller lifters) in with valvoline 10w-30, then mobil 1 synthetic 5 or 10w-30 AND mobil1 filter ever since. The number before the W is not as important as the number after the W.
Wal-mart was/is(?) selling 5 quarts for $22, so the difference between conventional and synth isn't that much.....
a) You have to remember that here in the northeast, you WILL encounter a traffic jam each and every time you drive. Even in the middle of night---due to constant construction. This ain't North dakota.

i ran Redline synth 10W-30 in the 350 and 305 (both flat lifters) just to be safe because it has extra/adequate zddp,
https://www.redlineoil.com/10w30-motor-oil
even though.....:

beags86 said:
Everything I have is synthetic.

Unpopular opinion... and you can debate if you choose. You don't need zinc additive if your engine is broken in.
I have flat tappet cams and don't add zinc or use a high zinc blend and they are fine.....
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Agree, IF you've got stock-ish valve spring pressures.

beags86 said:
Once the lobes have "worn in" it's of no benefit to add zinc, as the lobes are harded.
As I stated. My opinion is unpopular. But I have been just dumping oil in my flat tappet powered trucks with no ill consequences, for years.
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My .02: It's not a question of being broken in, it's a question of valve spring pressures. If you're running a more "intense" cam combo requiring stiffer springs, then you NEED adequate zddp. (and if you're going to spend the $$$ for all that, why not go roller at that point?)

Note: My above opinion is coming from a non-engine person standpoint(i'm more of a bolt-on assembler type) and that being said:

IF i were to go back to a flat lifter engine (and i don't see why i ever would), then i would run redline 10W-30 just to be safe; The price difference after 3 months or so isn't that much between conventional.
 
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vandelay industries said:
i broke the 4.3 v-6(roller lifters) in with valvoline 10w-30, then mobil 1 synthetic 5 or 10w-30 AND mobil1 filter ever since. The number before the W is not as important as the number after the W.
Wal-mart was/is(?) selling 5 quarts for $22, so the difference between conventional and synth isn't that much.....
a) You have to remember that here in the northeast, you WILL encounter a traffic jam each and every time you drive. Even in the middle of night---due to constant construction. This ain't North dakota.

i ran Redline synth 10W-30 in the 350 and 305 (both flat lifters) just to be safe because it has extra/adequate zddp,
https://www.redlineoil.com/10w30-motor-oil
even though.....:



Agree, IF you've got stock-ish valve spring pressures.



My .02: It's not a question of being broken in, it's a question of valve spring pressures. If you're running a more "intense" cam combo requiring stiffer springs, then you NEED adequate zddp. (and if you're going to spend the $$$ for all that, why not go roller at that point?)

Note: My above opinion is coming from a non-engine person standpoint(i'm more of a bolt-on assembler type) and that being said:

IF i were to go back to a flat lifter engine (and i don't see why i ever would), then i would run redline 10W-30 just to be safe; The price difference after 3 months or so isn't that much between conventional.
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I am only referring to stock engines.
Race or high performance engines should be treated as such.
 
dyeager535 said:
For what its worth, I'm not seeing anyone (manufacturer, articles, etc) that recommends over 5 years of shelf life for oil. Even synthetic, straight from Mobil. Can't recall how I stumbled upon that info, but it somewhat surprised me.

DexMerc from Warren, they also told me five years.

Not saying that to be a nanny...some of us like to hoard oil when it's cheap, but theoretically, when performance matters, it is probably not the best idea to store and use old oil. Mines just over 6 years, haven't seen any warning signs that it's "bad", but I doubt when stored halfway decently, an extra year is going to show evidence of starting to change.
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So whats the verdict on this? Ive got some mobil 1 full synthetic that is probably 10yrs old. New in bottle, never opened. Is it safe to use or should i just recycle it? Big waste of money (3–4 cases worth) to recycle but also dont want to cause premature wear (4 cases of oil < engine longevity). Not sure if the weight would have an impact, but in this case its 0w20.

I know there was a thread on this but dont recall what the outcome was for synthetic. Cant run in small engines (synthetic not recommended in those), and lubricating the chainsaw blade seems like a slow and painful process.
 
muddybuddy said:
So whats the verdict on this? Ive got some mobil 1 full synthetic that is probably 10yrs old. New in bottle, never opened. Is it safe to use or should i just recycle it? Big waste of money (3–4 cases worth) to recycle but also dont want to cause premature wear (4 cases of oil < engine longevity). Not sure if the weight would have an impact, but in this case its 0w20.

I know there was a thread on this but dont recall what the outcome was for synthetic. Cant run in small engines (synthetic not recommended in those), and lubricating the chainsaw blade seems like a slow and painful process.
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I would run them.
 
Mobil says right on their site that it's 5 years. https://mobiloil.com/en/faq/ask-our...experts/shelf-life-of-unopened-mobil-1-quarts

Personally I'd like to see some testing of "NOS" oil, to see what, if anything, has happened to it. Up to you whether you run it, I certainly prefer data to a recommendation. But I've gotten a pretty consistent "5 years" each time I've asked a manufacturer for the shelf life of petroleum lubricants.

I'm sure at least SOME of the 5 year recommendation is based on the fact that the manufacturer has no idea nor control of how the oil is stored...in direct sun, hot/cold cycles, high humidity, etc. I doubt they are just making it up, I'm sure they could be open to liability if the oil went bad and they didn't give a range.
 
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