Backdraft book says use 20w50 oil

[genolan]

I was reading my Backdraft manual and it states to use 20w 50 motor oil but after research it seems like it's to high a weight. I live in the north east and it gets pretty cold so I was thinking 5w 30 with high Zinc. Am I missing something?

[Bob In Ct]

If it were me, I'd be using 5W-30 Redline. It has higher ZDDP (1,200 PPM) and Moly than oils having the Starburst symbol. 20W-50 is very thick and would probably damage the engine during start-up especially during cold weather. If I had a roller cam and rockers I would just use 5W-30 Mobil1.

[genolan]

I agree Bob I'm switching to Valvoline VR1 SAE 10W-30 Racing Motor Oil

[bobcowan]

Depends on the engine installed. If the engine is built with loose tolerances in the bearings, you'll need the higher hot viscosity to maintain pressure.

But, you're right, 20W is pretty high for a new England winter. Red Line sells a 10-W50 oil. It's expensive, but could be just what you need.

[Bxx1]

Mobil 1™ 0W‐40 contains: Phos: 1000 PPM Zinc: 1100 PPM
Sufficient Zinc and Phos for roller lifters. I would not recommend for flat tappets due to the need for higher Zinc and Phos requirements for those engines.

OW for those cold early morning start-ups.
"Has excellent low temperature capabilities for rapid engine protection at start-up" from Mobil

"High performance engines Most operating conditions, from mild to extreme"
From Mobil.

Happy motoring.

[genolan]

BXX1 this makes sense can anyone give me a reason not to switch to Mobile 1 0w 40 from Castrol 20w 50. I have roller rockers but have no idea on bearing clearance. I took the car for a hard run last night and noted the pressure at idle 900rpm before (65PSI) and after (25psi)

[Slick61]

my engine builder (Keith Craft) recommended 20W-50... it's all I've ever used.

[Bob In Ct]

You should use the lightest oil which provides the desired pressure.

Bob

[bobcowan]

Originally Posted by genolan

BXX1 this makes sense can anyone give me a reason not to switch to Mobile 1 0w 40 from Castrol 20w 50. I have roller rockers but have no idea on bearing clearance. I took the car for a hard run last night and noted the pressure at idle 900rpm before (65PSI) and after (25psi)

No reason not to try a 0W-40 oil, and see what your hot pressures are. If they're too low, then go back to the "thicker" oil.

I'm not a huge fan of Mobile 1. It's not bad oil for most vehicles. It's not a true synthetic oil, but it's priced like one. IMO, that makes it a bad value.

Even in New England, a 10W-40 would not be a bad choice. 10W is rated down to -20*. So unless you're driving at temps lower than that, there's no need for a lower viscosity.

If you want a wide spread like 0W-40, you'll need to switch to a semi-synthetic like M1 or Syntech, or one of the 4 true synthetic oils.

[avdcav]

Brad Penn 20 50 Porsche says the same thing

[Morris]

We've been using Mobil 1 0w50 racing oil in our engines for many years....and my colleagues at Newman/Haas have been been using it as well......

We run motors harder then anybody on this board....and in many different engine types....(Ford,Chevy, Indy car type)......

By the way....it has a ZDDP level in the 1800's ppm.....great oil especially when you only start them....run them .....then park them for a while....

[blown871]

.. if the 'book said'..... "Jump off a bridge"... would you?

[genolan]

Originally Posted by blown871

.. if the 'book said'..... "Jump off a bridge"... would you?

Thanks for the great input!!

[cbreez]

Originally Posted by blown871

.. if the 'book said'..... "Jump off a bridge"... would you?

You are correct!!!

Oil pressure is affected by the pump and the pressure relief spring more than the "brand" and viscosity...
If you do your homework, really, and study hot temp viscosity... the difference is miniscule for the daily driver.
Water could be used as a lubricant except that it freezes and boils...tisk, tisk on the vis!

[Bxx1]

Not all motor oils from the same company are the same. Generally, I agree that Mobil 1 is not a top tier motor oil... But Mobil 0w-40 is one of their best oils. It has a VI index of 185. Most true synthetic oils have a VI above 165. Generally, the higher the VI the higher quality synthetic oil. I also like the fact that Mobil 1 0w-40 contains high amounts of Boron, which acts as a corrosion inhibitor and is considered an anti-wear additive (in addition to the Zinc and Phos.). I think it is a top quality oil, for my needs, in my 500 HP engine which gets used infrequently. I hate those cold starts but knowing it flows very well helps me overcome my apprehensions. Each to his own. Happy motoring.

[Got the Bug]

Originally Posted by genolan

Thanks for the great input!!

You've got to admit, it's kind of dumb that a manual made to provide details for a specific manufacturers chassis would call out a specification for a motor oil.

[genolan]

Great reference source for Mobile 1 oils

It looks like the 0w 40 is the best bang for the buck High Phosphorus*
Level and Zinc*Level and available at Walmart for $24 for 5 qt bottle. The 0w 50 racing oi is probably best for track and is $16 qt.Since I don't track the car and barley push it to the extreme I'm going with the 0w 40.

http://www.mobiloil.com/USA-English/...duct_Guide.pdf

[cbreez]

Originally Posted by Bxx1

It has a VI index of 185. Most true synthetic oils have a VI above 165. Generally, the higher the VI the higher quality synthetic oil.

Oh really, explain why??? Are you a chemist? What does VI mean to you? So more is better, eh?

[Bxx1]

I am only a chemist on the internet...

There is alot of info on the internet regarding motor oil, viscosity, etc. etc.
The link below could be a benefit in understanding some of the concepts of motor oil (especially regarding viscosity VI).
We all have our preferences for cars, motor oil, engines, etc. etc. I have found my preference for motor oil for my Cobra.

I hope readers find the link useful.

http://zddplus.labecon.com/TechBrief...0Viscosity.pdf

[eedeutsch]

My engine builder recommended 20w50 in summer and 10w40 in winter. He did
not specify any particular brand.