Conventional oil question

[Nissan101]

So my s13 burns a bit of ail, it had royal purple 20w50.(it also burn mobil 1 and shell)
Recently i did a oil change as being in university still i put the cheapest conventional 20w50 oil.
No oil consumption at all!
High RPMs
constant redline and no consumption
why does it consumes the cheap oil so much less?

 

[Leo99]

It likes conventional and dislikes synthetic? You found what it likes. That's good. Keep it up!

 

[Bud_One]

I used to have a 1993 B13 that would consume oil if you drove it easy, 1 qt per 500 miles. If you drove it like you stole it.. it would consume about a 1/2 qt every 4k.

 

[crazyoildude]

Its that way most of the time that is why i tell people that have used conventional all the time not to switch to synthetic when they have high mileage.
If you started with synthetic then its usually ok to stay with it.

 

[Doublehaul]

My brother had a camero with a LT1 that would eat QS green bottle...but nothing else. Switch to Mobil and all was good. Weird

 

[AKhan87]

Originally Posted By: crazyoildude
Its that way most of the time that is why i tell people that have used conventional all the time not to switch to synthetic when they have high mileage.
brilliant advice.

 

[ToadU]

Originally Posted By: crazyoildude
Its that way most of the time that is why i tell people that have used conventional all the time not to switch to synthetic when they have high mileage.
If you started with synthetic then its usually ok to stay with it.


That's a myth and not supported by the data, oil manufacturers or engine manufacturers. Synthetic is fully compatible with conventional and vice versa. Specific additive packages may be better suited for a particular engine or operating parameters. Oil weights can have a huge effect in consumption. However, there is no difference between a conventional and synthetic that's the same weight. In other words a 10w30 Syn and conventional are 10w30 weight oil--the same weight and thickness.

 

[bigt61]

Originally Posted By: ToadU
Originally Posted By: crazyoildude
Its that way most of the time that is why i tell people that have used conventional all the time not to switch to synthetic when they have high mileage.
If you started with synthetic then its usually ok to stay with it.


That's a myth and not supported by the data, oil manufacturers or engine manufacturers. Synthetic is fully compatible with conventional and vice versa. Specific additive packages may be better suited for a particular engine or operating parameters. Oil weights can have a huge effect in consumption. However, there is no difference between a conventional and synthetic that's the same weight. In other words a 10w30 Syn and conventional are 10w30 weight oil--the same weight and thickness.

Yeah, it's a myth all right - it's only supported by the people who have tried it, including me. Synthetic leaks and usage in high mileage older cars are common, no matter what book or article says otherwise.

 

[ToadU]

It's a myth per science and testing. One-off testimonials are not proof positive. Oil usage and leaks are common in older high mileage cars in general. Changing from synthetic to conventional and back again or mixing has no impact on an engine. It's just somthing people started saying way back when synthetics were new to the market and there was a lack of understanding.

 

[BrocLuno]

Originally Posted By: ToadU
It's a myth per science and testing. One-off testimonials are not proof positive...


It is to folks who have experienced it, me included ...

 

[Nissan101]

its not leaking, its just burning. When driving at low speed there is no consumption but at high speeds and high rpms its burns a bit

 

[Jake777]

Originally Posted By: BrocLuno
Originally Posted By: ToadU
It's a myth per science and testing. One-off testimonials are not proof positive...


It is to folks who have experienced it, me included ...


Ill chime in here. I have a 2005 Honda Odyssey that spent all of 125,000 miles on conventional oil from various shops down to VWB and Mobil Super when I did them myself. After learning how hard on oil that motor is and how the oil life monitor system lets you go too long and trouble can come of it. Any way I thought lets switch to PP and it was great ran smooth seriously felt like it made a bit more power and I was happy. About 3,000 miles later big leaks from the V Tech module, Rear Main Seal and Oil Pump under the timing cover. General idea is I had some nasty build up that likely created false seals keeping the oil from conditioning the seals like it should so they started to dry out. PP cleaned it up like a champ leaving no false seals behind and now the freshly exposed old seals started leaking fast. Changed out the V Tech selinoid seal and switched to Pennzoil High Mileage Conventional and the RMS and oil pump leak slowed to a few drips every few days. Bottom line is yes you are correct that the synthetic didn't cause the leak in and of itself but like the crazyoildude said sometimes if you aren't 100% sure of the inside condition of a high mileage motor it is safer to leave the super high detergency synthetics alone. Its not that were afraid that synthetic causes the leak its that we who have experienced it know how this condition can exist and turn into a fun leak.

 

[BrocLuno]

If it's burning it, you might try a ring soak... Sometimes that will free up stuck rings and they will seal better for maybe another 10K or so. Worn motors are just that. But sometimes they can be helped along