Synthetic vs Conventional oil

[swampratt]

I will start this argument I mean thread.

Years ago when synthetics were becoming popular I switched to Mobil 1 synthetic.
I noticed my MPG came up.
Win for sure as I was driving more than 70,000 miles a year and the wife was also.
That is just recorded miles on 2 of the 6 vehicles we drove.

I had a lot of miles to test things like tire pressure and oils and greases and transmission fluids.
One thing that was stated way back then was you could not mix synthetic with conventional oil.

Well I mixed it and nothing bad happened.
I heard you can't mix transmission fluid types.

Well let me test that so every 20,000 miles I mixed Type A type F and dextron and changed the fluid in my C5 Ford transmission.
That engine and trans outlasted the vehicle, 376,000 miles no issues.

Now lets move on to break in.
I heard use break in oil or your rings will not seat.
Not true for me at all if the rings are Moly faced and the surface was a 620 plateau hone.

I did the break in in a 302 ford .030 over bore.
200 open pressure on the valve springs.
I ran Mobil 1 10-30 synthetic right off the bat and drove it on that oil to Peoria AZ from Yukon Ok and it used 1 quart of oil.

I changed it there and went on to Oregon then took the north east path home and the rest of the trip the 302 did not use any oil.
5500 miles round trip.
Yes that engine was honed with torque plates installed.

I built another 302 years later and No TQ plates and it used a quart at 3000 miles.
Thin early 80's 302 engines.

I use Synthetics in my cars now except for the V8 chevy with flat tappet cam i use Valvoline VR1 racing.
And I use a dedicated break-in oil Gibbs brand.
But valve spring pressures and cam profile is not stock.

No issues.

I no longer use Mobil 1 as of 2007 the formula reduced ZDDP and a different anti wear package was brought in.
My MPG took a hit and engines became tickity.
I even recently tried 2 different Mobil 1 synthetics the European and the High mileage which I think just has more Molly.

Both were tickity fails.
Initial start up and idle were tickity in the 1.8 Toyota engines.

My Diesel Rotella T6 oils does not do that neither does the Castrol Edge.
Buddies Honda was ran forever on Mobil 1 synthetic and I swear he had a rod knock.
Got louder the more he revved it up.
He stated the last 2 years it sounded like that.

He sent off an oil sample to Blackstone labs and they gave his engine a good bill of health basically.
So i convinced him to change from his favorite and stick in some T6.

That knock went away.
His 6.0LS was running Mobil synthetic also and he changed it to T6.
At 1/2 a tank of fuel use his odometer would show 200 miles driven every time but now with the T6
it shows 240 miles driven.

Something happened with Mobil oil and it saddens me as I want to like it but it does not like me.

Good day.
About time to make a fire in the wood insert.

 

[Roy14]

https://540ratblog.wordpress.com/2013/06/20/motor-oil-wear-test-ranking/
If you really want to nerd out on oil, this is the place to go. He has some really interesting findings.

FWIW, he hates rotella. I’ve used it for years with no issues in everything from old dirtbikes to heavy equipment, but I’m not hard on my stuff either. I’ve switched to JD 15-40 for my diesel motors (because amsoil 0-40 is just too expensive) and for gas motors, I just buy the best deal on synthetic 5-30. If I remember correctly, the last time I checked his list he had Quaker state full synthetic 5-30 as the best testing oil he’d tried.

 

[Forgalspop]

About synthetic and break-in. My 2020 Chevy with 6.6L came from the factory with Chevrolet's recommended synthetic oil. Drove it 2,000 miles and switched to Mobil-1 which is essentially the same as Chevrolet's recommended oil and approved by Chevrolet. No problems so far, but might look into switching to Rotella T6 once warranty expires.

 

[swampratt]

If you really want to nerd out on oil, this is the place to go. He has some really interesting findings.

I am a member on Speedtalk and Team chevelles and many other car sights and 540rat does do a lot of testing.
But he gets a lot of haters also.
Some of the oil tests do not take into account the heat and aeration that you get in a real running engine.
But he still has some very interesting information.

 

[swampratt]

About synthetic and break-in. My 2020 Chevy with 6.6L came from the factory with Chevrolet's recommended synthetic oil. Drove it 2,000 miles and switched to Mobil-1 which is essentially the same as Chevrolet's recommended oil and approved by Chevrolet. No problems so far, but might look into switching to Rotella T6 once warranty expires.

For LS engines or newer stuff which I do not like I would use Driven brand LS oil.
In fact that is what my friends and my cam grinder buddy use in their NOT stock ls engines.
500+ HP deals That do get beat on.

But if the Mobil is working for you and not ticking on start up or sitting there at idle ticking then I see no issue with the choice of oil.

I just can't run an oil that makes my engine noisy.

 

[Mr.Glock]

I have used Rotella T6 Synthetic in 5 Honda Goldwings, 3 over 200k and 2 over 150k and never used a drop and use it in all me ATVs and UTVs. Have used Rotella 15/40 T4 Dino oil in 11 Dodge Diesels, and all my Dozers/Tractors and Equipment with great results.

 

[Roy14]

I am a member on Speedtalk and Team chevelles and many other car sights and 540rat does do a lot of testing.
But he gets a lot of haters also.
Some of the oil tests do not take into account the heat and aeration that you get in a real running engine.
But he still has some very interesting information.

I have used Rotella T6 Synthetic in 5 Honda Goldwings, 3 over 200k and 2 over 150k and never used a drop and use it in all me ATVs and UTVs. Have used Rotella 15/40 T4 Dino oil in 11 Dodge Diesels, and all my Dozers/Tractors and Equipment with great results.

It’s hard to not doubt him on the rotella stance, as I’ve had good luck with it and so have most other people I know who run rotella in equipment and smaller engines. I do think his stance on oil additives being useless at best and harmful at worst makes sense.

I switched to JD due to cost and availability, not specifically because of his dislike for it.

 

[magna19]

Oil debates are funny. Especially when a backyard mechanic is complaining about brand of oil that is used in expensive factory cars/trucks that are under warranty. Then comparing motors that are rebuilt/modified/driven by someone else/ETC. Most of time when a motor issue cant be found or determined correctly the oil gets the blame. Its what some mechanics do.

 

[enuf]

So, we are supposed to change our oil and not just add to it?

 

[HoLeChit]

In my experience, John Deere diesel engine and hydraulic oil are the best in the business, for equipment and passenger vehicles.

For cars, I only use synthetic, and it’s almost always Mobil 1. For the wife’s Lexus and when I had my BMW they get what the dealership serviced them with, so OE branded synthetic.