I have a 1984 chevy suburban with the 350 v8. I was looking at the dipstick and it said use sf oil. I was wondering if an sn oil would be ok in this engine. I just bought it. It previously has had a diet of 10-30 or 10-40 stp,supertech,and whatever else was on sale
1984 suburban oil help.
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Originally Posted By: jdawg89
I have a 1984 chevy suburban with the 350 v8. I was looking at the dipstick and it said use sf oil. I was wondering if an sn oil would be ok in this engine. I just bought it. It previously has had a diet of 10-30 or 10-40 stp,supertech,and whatever else was on sale
Yes, SN simply supersedes SF and is a better oil.
If you're worried about the lower ZDDP content, you can use 10W-40, which, unlike 10W-30, has no restriction on it. 10W-40 will also reduce your oil consumption. 10W-30 should also be fine though and will give you a slightly better MPG.
I have a 1984 chevy suburban with the 350 v8. I was looking at the dipstick and it said use sf oil. I was wondering if an sn oil would be ok in this engine. I just bought it. It previously has had a diet of 10-30 or 10-40 stp,supertech,and whatever else was on sale
Yes, SN simply supersedes SF and is a better oil.
If you're worried about the lower ZDDP content, you can use 10W-40, which, unlike 10W-30, has no restriction on it. 10W-40 will also reduce your oil consumption. 10W-30 should also be fine though and will give you a slightly better MPG.
Yes older engines can use new oil with out any issues,its all back spec'd for use.
That old girl is going to have flat tappets so a good slug of ZDDP will definitelyly help.
That old girl is going to have flat tappets so a good slug of ZDDP will definitelyly help.
Do you think a hot rod oil (like z-rod or that edelbroc oil with high zddp) would be a good choice? And ok, I know that sn is better,just checking compatibility. It hardly uses oil,and at 10mpg on a good day idc about improving or not lol.
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Valvoline VR1 has high zddp.
Its a generic 350- its not going to be too picky unless you've got a jacked up cam and monster valve springs in there. If you want to be extra kind to its flat/sliding lifters, use something like Valvoline MaxLife, one of the other high-mileage oils, or an HD oil like Rotella. Don't use racing oil- not enough detergent for street use in some of those.
Rotella T6 for sure. Higher zinc and its a nice stout synthetic with cheap gallons at Wal-Mart.
Or T5 10w30 if he wants conventional.
Regarding ZDDP, contrary to what most people think, HDEOs like Rotella have 1,200 ppm maximum limit (on P). On the other hand, PCMO xW-40 (and xW-50) has no limit on ZDDP. Therefore, chances are that you will get more ZDDP with a PCMO 10W-40 than with Rotella. On top of that, PCMO additive pack is more tailored toward gas engines.
Originally Posted By: Gokhan
On the other hand, PCMO xW-40 (and xW-50) has no limit on ZDDP. Therefore, chances are that you will get more ZDDP with a PCMO 10W-40 than with Rotella.
Be careful. Just because an oil has "no limit" as to how much ZDDP it can contain does not mean it will have really high amounts. VOAs have shown that just grabbing a 10w-40 with the hopes it has high ZDDP is a bit of a shot in the dark. They can easily have SN/GF-5 levels of ZDDP in them. With HDEOs, you're a lot less likely to see that.
Heck, as we see in some vintage VOAs here, in the days of supposedly limitless ZDDP, we quite often saw levels of ZDDP that would be acceptable today in SN/GF-5 oils. My view is that if it's a modern PCMO, regardless of grade, assume SN/GF-5 ZDDP levels unless a VOA or a spec sheet shows otherwise.
On the other hand, PCMO xW-40 (and xW-50) has no limit on ZDDP. Therefore, chances are that you will get more ZDDP with a PCMO 10W-40 than with Rotella.
Be careful. Just because an oil has "no limit" as to how much ZDDP it can contain does not mean it will have really high amounts. VOAs have shown that just grabbing a 10w-40 with the hopes it has high ZDDP is a bit of a shot in the dark. They can easily have SN/GF-5 levels of ZDDP in them. With HDEOs, you're a lot less likely to see that.
Heck, as we see in some vintage VOAs here, in the days of supposedly limitless ZDDP, we quite often saw levels of ZDDP that would be acceptable today in SN/GF-5 oils. My view is that if it's a modern PCMO, regardless of grade, assume SN/GF-5 ZDDP levels unless a VOA or a spec sheet shows otherwise.
I'd think QS Defy would be a good choice, it's got a good amount of ZDDP. Otherwise, a 10W-30 HDEO would work well too.
Originally Posted By: daman
Yes older engines can use new oil with out any issues,its all back spec'd for use.
That old girl is going to have flat tappets so a good slug of ZDDP will definitelyly help.
28 is pretty young for a lady...
Yes older engines can use new oil with out any issues,its all back spec'd for use.
That old girl is going to have flat tappets so a good slug of ZDDP will definitelyly help.
28 is pretty young for a lady...
Honestly, chances are that any synthetic 0W-30, 5W-30, or higher, or any dino 10W-30 or higher should be fine with this engine. It's not clear if more ZDDP helps, as today's oils have other AW/EP additives such as moly in the mix, which make up for lower levels of ZDDP. High-mileage oils would be fine too, and chances are that no one can tell which one -- conventional, synthetic, high-mileage, 10W-30, 10W-40, etc. -- will produce less wear, if it will make any difference at all to begin with.
Some older engines can benefit from thicker oil though, and there is a chance that xW-40 might be more suitable for you if this is the case for your engine. You can choose from 10W-40 dino PCMO, Mobil 1 0W-40 synthetic, 5W-40 HDEO synthetic, as well as super-thick 15W-40 HDEO dino out there.
However, as I said earlier, xW-30 might be sufficient and perfectly fine too, but if you go 0W-30 or 5W-30, make sure it's synthetic so that it doesn't shear much.
However, as I said earlier, xW-30 might be sufficient and perfectly fine too, but if you go 0W-30 or 5W-30, make sure it's synthetic so that it doesn't shear much.
Originally Posted By: jdawg89
I'm just a little nervous about syn. In such an old motor that's always had dyno. And rotella 15-40 will not work in winters up here...LOL.
This is the oil-recomendation chart for your engine:
If you don't want to change the oil type, just go with a name-brand 10W-40. Stay away from store brands, which could sometimes be poor-quality. Whatever major brand on sale is a good way to save money.
If you really want a fancy oil, go with Mobil 1 0W-40 but it will be expensive unless it's on sale.
10W-30 dino should also be OK.
Going from dino to synthetic shouldn't hurt anything -- not much different than changing the oil brand.
High-mileage oils are also OK.
Chances are that even modern dino 5w-30 (as opposed to early-to-mid 80s dino 5w-30) is OK. Synthetic 5W-30 (which doesn't shear as much as dino 5W-30) is definitely OK. Virtually any oil should be OK for this engine.
PS: It's funny that in the chart footnote they put 5W and 5W-20 in the same very thin category, while OKing sraight 10W. It gives you an idea on how much early-to-mid 80s multigrades sheared -- 5W-xx oils shearing to perhaps almost 5 weight. This is no longer a problem with modern multigrades and chances are that even a modern 5W-20 or 0W-20 would be OK with this engine.
I'm just a little nervous about syn. In such an old motor that's always had dyno. And rotella 15-40 will not work in winters up here...LOL.
This is the oil-recomendation chart for your engine:
If you don't want to change the oil type, just go with a name-brand 10W-40. Stay away from store brands, which could sometimes be poor-quality. Whatever major brand on sale is a good way to save money.
If you really want a fancy oil, go with Mobil 1 0W-40 but it will be expensive unless it's on sale.
10W-30 dino should also be OK.
Going from dino to synthetic shouldn't hurt anything -- not much different than changing the oil brand.
High-mileage oils are also OK.
Chances are that even modern dino 5w-30 (as opposed to early-to-mid 80s dino 5w-30) is OK. Synthetic 5W-30 (which doesn't shear as much as dino 5W-30) is definitely OK. Virtually any oil should be OK for this engine.
PS: It's funny that in the chart footnote they put 5W and 5W-20 in the same very thin category, while OKing sraight 10W. It gives you an idea on how much early-to-mid 80s multigrades sheared -- 5W-xx oils shearing to perhaps almost 5 weight. This is no longer a problem with modern multigrades and chances are that even a modern 5W-20 or 0W-20 would be OK with this engine.
I;d go to Wally World and buy M1 HM 10W40 in the 5 qt jug for around $25. Find a good oil filter, change it every 5-6K and be done with it.
Originally Posted By: Gokhan
Regarding ZDDP, contrary to what most people think, HDEOs like Rotella have 1,200 ppm maximum limit (on P).
Well, that's not 'contrary' to what I believe, its EXACTLY what I believe ;-)
And ~1000 PPM in a balanced additive package like Rotella has is more than enough for anything except the most extreme high-lift cam with insane valve spring pressures.
IMO its misguided to think that ZDDP is the only thing to consider. I'd rather have a balanced additive package with some ZDDP and some other anti-wear additives in the mix than some mega-high ZDDP oil that caters to the current obsession with ZDDP and short-changes detergents and other additives. Rotella (and other similar HDEOS) are a proven commodity, as are HDEO and better balanced 'street performance' oils from Redline, RP, Amsoil, Mobil, and others. M1 0w40 has great AW properties. So does their 15w50, if you want to go that heavy (and a 350 certainly wouldn't mind it except in the coldest weather.)
But as I said, for a garden-variety Chevy 350... just quit worrying and put a good name-brand oil in it. It needs no more pampering for its roller-less cam than does a Jeep 4.0.
Regarding ZDDP, contrary to what most people think, HDEOs like Rotella have 1,200 ppm maximum limit (on P).
Well, that's not 'contrary' to what I believe, its EXACTLY what I believe ;-)
And ~1000 PPM in a balanced additive package like Rotella has is more than enough for anything except the most extreme high-lift cam with insane valve spring pressures.
IMO its misguided to think that ZDDP is the only thing to consider. I'd rather have a balanced additive package with some ZDDP and some other anti-wear additives in the mix than some mega-high ZDDP oil that caters to the current obsession with ZDDP and short-changes detergents and other additives. Rotella (and other similar HDEOS) are a proven commodity, as are HDEO and better balanced 'street performance' oils from Redline, RP, Amsoil, Mobil, and others. M1 0w40 has great AW properties. So does their 15w50, if you want to go that heavy (and a 350 certainly wouldn't mind it except in the coldest weather.)
But as I said, for a garden-variety Chevy 350... just quit worrying and put a good name-brand oil in it. It needs no more pampering for its roller-less cam than does a Jeep 4.0.
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