conventional motor oil gone, synthetic blend in older vehicles?

Messages
7
After reading this forum it seems conventional oil is gone and i haven't been able to find any at the local stores. How will the synthetic blend affect older high mileage vehicles?

I have two older high mileage vehicles that do not leak or use any oil. One is a 1996 Tacoma with 210,000 miles on it and the other a 2011 corolla with 190,000 miles that gets driven 20,000 + miles a year now.

These two vehicles have never seen synthetic oil. The corolla book says to use 0w-20 or 5w-20. I've been using pennzoil 5w20 conventional all it's life. The tacoma i've always used 10w-30 conventional.

Should i use full or synthetic blend in these vehicles?

Some say it can cause a leak others say it will be fine. I did look at the specs sheets for pennzoil 5w20 conventional vs 5w-20 synthetic blend and to me i don't see much of a difference.

In my newer vehicles i have used full synthetic since day one with zero issues but they where new without a lot of miles.

I've never used the so called high mileage oil as i have no leaks and never have to add oil between changes.

Thanks for the help! :)
 
Messages
377
Location
Maryland
Well, conventional motor oil really has not been "conventional" for a few years now. They have been a blend of various base stocks which are conventional and synthetic in order to meet various manufacturers and industry requirements since SN oils came into the picture. Sometimes product data sheets mentioned the oils were a blend and sometimes they did not.

It really does not matter which type of oil you choose - a synthetic blend oil or a "fully synthetic" oil. The final product has to meet or exceed a given specification for a given oil such as 0W20 or 5W20. Plus your engine will not know the difference between a synthetic blend and a "full synthetic" motor oil.

Since your engine is not dripping or leaking oil, you do not need to worry about using a high mileage motor oil. However, if you go with, say, a full synthetic 0w20 or 5w20 oil, you might initially see some seepage or a few drips, and this is not so much due to the change to a fully synthetic motor oil, but is due to a different additive package being used than what your previous oils used. Give it a few oil changes and the seepage and drips should go away. If not, then you can consider using a high mileage motor oil which will likely have more seal conditioners present and have a slightly higher operating viscosity than the oils you have been using.
 
Messages
7,500
Location
Roanoke Virginia
Yes unfortunately conventional for the most part is gone. Still available some places but I’m not paying a high parts store price for it. I’d try a blend first. Synthetic does NOT cause leaks. I’ve had a few leaks form but it’s because all the loose places get pretty cleared out with the synthetic from my understanding. I try to only run synthetic if it’s recommended from the factory.
 

Chris19

Thread starter
Messages
7
Why is conventional gone? I get that new cars don’t use it but what has changed are there some new guidelines.

I have found some conventional online for sale but it seems like they are charging double the price.

I will just use the blend and see what happens.

thanks for the help.
 
Messages
595
Why is conventional gone? I get that new cars don’t use it but what has changed are there some new guidelines.

I have found some conventional online for sale but it seems like they are charging double the price.

I will just use the blend and see what happens.

thanks for the help.
In order to meet API SN.

The blend or full synthetic should work fine for you.

Let us know what happens.

Good luck!
 
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Messages
377
Location
Maryland
Why is conventional gone? I get that new cars don’t use it but what has changed are there some new guidelines.

I have found some conventional online for sale but it seems like they are charging double the price.

I will just use the blend and see what happens.

thanks for the help.
Likely because the oil companies and blenders do not sell enough anymore for it to be a viable stand alone product. They probably figure that the consumer will purchase a "higher quality" synthetic blend oil for the same price as a perceived to be "lesser quality" conventional oil.

I am sure that conventional oils will stick around for a while yet, but will be considered more of a boutique oil than a mainstream oil.
 

Chris19

Thread starter
Messages
7
My local advanced auto has FRAM conventional oil not sure who actually makes it.

I went to two Walmarts and they have zero, tractor supply, Lowe’s, home depo. etc
 
Messages
519
Yes unfortunately conventional for the most part is gone. Still available some places but I’m not paying a high parts store price for it. I’d try a blend first. Synthetic does NOT cause leaks. I’ve had a few leaks form but it’s because all the loose places get pretty cleared out with the synthetic from my understanding. I try to only run synthetic if it’s recommended from the factory.
Used to run only conventional motor oil , until conventional became scarce, now its synthetic blends but no problems with that.

Older synthetics had more esters in it, would cause seal imbalances but thats gone now.
 
Messages
18,389
Location
Silicon Valley
They are all marketing in the US anyways. The formal definition is just the amount of unsaturated or sulfate stuff inside that would go bad much quicker. By reducing these stuff your oil will last longer.

It doesn't mean the "syn" oil will be magically better than the dino oil, nor these cheaper newer syn oil will cause seal problem like in the early days. If you are concerned get the thicker syn to mix in the blend and call it a day (i.e. 4 qt of 5w20 + 1 qt of 5w30).

I have been running syn in all my cars and 2 are already 270k miles, syn will leak and dino will leak, unless i run the dino out so long it thicken up and turn from 5w30 into 10w40 or 20w50.
 
Messages
224
Location
UK
emission control and fuel economy has pushed car makers towards thin synthetic fuel.
If you are saying, non synthetic oil is becoming difficult to source, the only reason I can think of is that the profit margines are much higher for semi synthetic oil (group III?). Cheaper to product but misleading labelled to a price 80% of a full synthetic one.
The oil leak issue is interesting. Over the years the internal of your engine can accumulate deposits left behind by the oil and rubber seals can also become harder.
Now synthetic oil can circulate much better and go through the tiniest of clearances not to mention dislodge the deposits inside the engine. Here is the potential of leaks or blockage. You can find a lot of write up about this potential issue.

I would use group III oil if I were in your situation to start with
 
Messages
2,770
Location
San Rafael, CA
At work we sell many brands of oil. Even our house brand "conventional" is API SP rated now and it's my understanding that means it's practically a synthetic blend. Castrol, Valvoline, Pennzoil "conventionals" are all labeled "synthetic blend" in 5w-20 and 5w-30. 10w-30 and beyond are still labeled conventional.

I have to explain this a hundred times a day. There is no problem using the new oils labeled "synthetic blend" if you were buying conventional before. They are backwards compatible. If you have oil consumption or an oil leak that's not the oils fault.
 
If you think you must use conventional motor oil, check rural convenience stores. Some of them carry "no-name" (obscure brand) oils. If that store's stock of the no-name brand includes nondetergent 30–weight, then I'd bet the 5W-30 etc. are conventional.

The problem is that I wouldn't trust any of that brand of oil, as there's zero reason to sell nondetergent oil as motor oil today (in my opinion), and what does that say about the quality of the other weights? I wouldn't even use any of that brand in my lawn mower.

Synthetic blend from a well known company should be just fine. As others here hinted, you've probably been using it already without knowing it.
 
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