Any difference between semi syn and full syn ?

Status
Not open for further replies.
K

kenpoed

Joined
Nov 8, 2012
Messages
148
Location
Pennsylvania
If I do a 6k run non severe driving on a pennzoil gold semi syn vs a platinum full syn would you think it would make any difference over a 300k engine lifetime? In other words do you think I can get that much out of my engine either way?

Many of the bitogs seem to get wound up about how long you can run oils with oil analysis, but if I run a semi syn with a 6k interval in the long run don't you think my engine will be just as clean?

Curious about others thoughts.
 
Will your engine ever see 300.000 miles? I have seen cars with 300,000 miles with Jiffy lube oil and filter changes. This isn't the 1960's major brand oils are excellent these days. The question should be does my engine require syn oil to survive.
 
The key to longetivity is not the oil quality between stuff on WalMart shelves, but rather the frequency of oil changes. There are engines that got killed at very low mileages because owners thought they could easily follow the 25k mile OCI with Amsoil. And there are people who get the cheapest conventional oil change, but do it every 3k-5k miles and easily get the engine to outlast the rest of the vehicle. I'm a strong believer in frequent oil changes rather than extended OCIs. The longer the oil is in the engine - the more deposits it will collect. I prefer having minimum deposits and peace of mind with 5k oil changes.
 
Last edited by a moderator:
I can't say for sure. I use synthetic fluids where ever I can. For me, it just helps me sleep better. I have had some vehicles run North of 400k miles using synthetics, some worked hard and never an issue. Could a conventional or blend do that. May be, but I would have lost a ton of sleep over it in the process. If it meets the specs it's fine. SN ,Dexos, HT-06, MB 229.5, 0w20 are all good specs. Could some be made by using a blend, sure. Others require a full synthetic like I believe 0w20 weights do. Are there 0w20 blends?
 
Last edited:
I do 10K with M1 oils and have for 39 years. My engines stay very clean, use no oil in 10K, and show no sign of engine wear.
 
I'm in the "thicker is better" cheap oil camp (goes with my thick skull). As long as the thicker better cheaper meets the ambient requirement, it's gotta be better than best "thinner worse" expensive engine oil.
Which reminds me, Wal*Martin's have 5 gallon pails of 15W40, 30 & 40 on for $47 Canuck bucks, which works out to about $35USD.
This means "Frampa" can change the oil in the truck for $20 at 5K miles, 4 or 5 times a year for a C-note.
 
Originally Posted By: tig1
I do 10K with M1 oils and have for 39 years. My engines stay very clean, use no oil in 10K, and show no sign of engine wear.


A friend just bought an RX350. The oil change interval is 10k with the recommended synthetic oil.

On her RX300 I would not go 5k on synthetic oil since engine design was prone to sludge.

On my Elantra will be doing 6-month oil changes at dealership which is about 3,750 miles. That also is the severe service. It is what Hyundai recommends. My dealership uses Valvoline Premium Conventional which is semi synthetic.

For longer intervals synthetic is the way to go.
 
Originally Posted By: kenpoed
Ibut if I run a semi syn with a 6k interval in the long run don't you think my engine will be just as clean?


You could use a "conventional" for 6k and your engine will be just as clean. Relax.
 
Originally Posted By: Vlad_the_Russian
There are engines that got killed at very low mileages because owners thought they could easily follow the 25k mile OCI with Amsoil.


And the proof of these dead engines is???
 
On the lighter side...

When pondering the difference between the two,, the full syn is simply more excited than the semi syn. If you have full syn, it can go much longer than the semi before becoming too weak. All this assumes no premature loss of fluid via the drain hole.

6k can likely be done by either as long as they meet the required spec.
 
Oh the full synthetic might keep it a bit cleaner. If its Pennzoil Gold vs Platinum only longevity and a slight throttle response might be it. For a couple bucks more go QSUD or Amsoil OE.
 
Originally Posted By: Vlad_the_Russian
The key to longetivity is not the oil quality between stuff on WalMart shelves, but rather the frequency of oil changes. There are engines that got killed at very low mileages because owners thought they could easily follow the 25k mile OCI with Amsoil. And there are people who get the cheapest conventional oil change, but do it every 3k-5k miles and easily get the engine to outlast the rest of the vehicle. I'm a strong believer in frequent oil changes rather than extended OCIs. The longer the oil is in the engine - the more deposits it will collect. I prefer having minimum deposits and peace of mind with 5k oil changes.


Amen +1
 
Originally Posted By: Pablo
Originally Posted By: Vlad_the_Russian
There are engines that got killed at very low mileages because owners thought they could easily follow the 25k mile OCI with Amsoil.


And the proof of these dead engines is???


Yeah. I'm dying to know myself.
 
Originally Posted By: Marco620
Oh the full synthetic might keep it a bit cleaner. If its Pennzoil Gold vs Platinum only longevity and a slight throttle response might be it. For a couple bucks more go QSUD or Amsoil OE.


How is throttle response affected by running syn vs semi, given the same weight? I can *maybe* see that you *might* realize a difference way below 0°f temps before the oil is up to normal operating temp. But, even then, not sure you'd see a difference between the two when only measuring with the seat-o-the-pants dyno.
 
Originally Posted By: kenpoed
If I do a 6k run non severe driving on a pennzoil gold semi syn vs a platinum full syn would you think it would make any difference over a 300k engine lifetime? In other words do you think I can get that much out of my engine either way?

Many of the bitogs seem to get wound up about how long you can run oils with oil analysis, but if I run a semi syn with a 6k interval in the long run don't you think my engine will be just as clean?

Curious about others thoughts.


Seriously? You're wasting your money if you're only running 6,000 miles. Conventional oils that are API SN/GF-5 can go 7,500 miles with ease these days.

But I'm a hypocrite I guess, since I follow the OEM recommendation of at least semi-synthetic in my Ford, and it's OEM OCI is 5-7.5k normal usage, and 3k heavy duty usage.

If you're vehicle doesn't require semi-syn or synthetic, using conventional oil is your best option if you're only running to 6,000 miles.
 
Originally Posted By: 4ever4d
At this point in time most "conventional oils" are semi synthetic.


Yeah this seems it may be true. Castrol GTX and Chevron Supreme are both rumored to be a synthetic blend. Many others could be too but I mention these two due to some discussions I have seen here about them.
 
MRtv you are correct. In fact Chevron Havoline, Valvoline, Castrol GTX all mention in their PDS that these "conventional oils" are in fact synthetic blends. So, this is no longer rumors but in fact in writing on their PDS.
 
Status
Not open for further replies.

Similar threads

N
Best value on Full Syn motor oil
2 3
Replies
52
Views
6K
FlyingTexan
L
Qs euro 5w40
Replies
10
Views
1K
JavierH19
D.R.S
5.7 Chevy oil
Replies
10
Views
772
Bear906
F
Oil Recommendation Nissan VQ40DE + opinions on current oil/filter
2
Replies
31
Views
1K
ka9mnx
M
Valvoline restore and protect ford 3.7
2 3
Replies
58
Views
3K
JoelB
Back
Top