Best oil to use?
Best oil to use? I am breaking in a motor and I used Rotella 15W-40 for the first 500 miles. Then I went to Pennzoil 5W-20 conventional for the next 2000 miles. I just finished talking to my engine maker and he recommended 10W-30 conventional. Should I drain the 5W-20 and put in 10W-30 or just stay with what I got? He also didn't recommend any specific brand but he did say that he was against Royal Purple, which I have used for years. I think I am going to start going with Valvoline VR1 racing 10W-30 synthetic when I get through this break in cycle.
What do you guys think?
What do you guys think?
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
Were you showing good pressure with 5W-20? Too many engine guys are old school and think 10W-30 is the minimum that should be used in any engine. If your engine has standard clearances, 5W-20 should be fine.
On The Tree
Joined: Aug 2007
Posts: 141
Likes: 2
First off, there is no "Break in Period", build it and run it. Second, just use a good quality oil, preferably a oil that is race engine approved due to the fact it has better "add pack" in it for extreme operation. Royal Purple is pure garbage, I wouldn't run it in a beater car. Just ask the engine builder for proper specs on weight and run a quality race oil and a good filter (not all filters measure up) and go beat on it and see what it does, no such thing as break in period... All you need to do is give the rings a chance to seat / bead properly and this doesn't take 500 miles, this will be done sooner then you think using conventional oils.
Oh and don't use diesel oil to break in a gas engine either, there is no reason for this, the "add pack" is not for a gas vehicle and it can damage Cat Converter if you have them.
check this site out for more info:
https://www.bobistheoilguy.com/forum...s.php?ubb=cfrm
Oh and don't use diesel oil to break in a gas engine either, there is no reason for this, the "add pack" is not for a gas vehicle and it can damage Cat Converter if you have them.
check this site out for more info:
https://www.bobistheoilguy.com/forum...s.php?ubb=cfrm
Last edited by SRT8.Acelleration; Aug 24, 2018 at 06:36 PM.
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Off the shelf oils are so good these days that they are just fine. Stick with the weight of oil that the engine was machined to use. I personally like pennzoil after it was reformulated about 10 years ago, I had a 2004 Sierra I bought at 80k and sold at 190k. Around 185k I replaced the valve cover gaskets, the engine still looked new inside. There were only a couple of oil changes I did where I didn't use pennzoil. I personally like Mobil and Valvoline as well.
Tolerances are getting tighter and oils are getting thinner. I often see people run heavy weight oils in their LS hotrods, and when I ask why, the answer is always "cause it's a built motor"
"Built" has nothing to do with the viscosity you run, how it was built does.
Lastly, often times when say the rod or main bearings were set at looser tolerances for heavier oil, higher weight oil is recommended. Well what about all the other tolerances throughout the engine?
Long story short, you're most likely setup to be running 5w-___ or 10w-___, since (safe to assume) most of the tolerances in your engine are still OE spec clearances.
Tolerances are getting tighter and oils are getting thinner. I often see people run heavy weight oils in their LS hotrods, and when I ask why, the answer is always "cause it's a built motor"
"Built" has nothing to do with the viscosity you run, how it was built does.
Lastly, often times when say the rod or main bearings were set at looser tolerances for heavier oil, higher weight oil is recommended. Well what about all the other tolerances throughout the engine?
Long story short, you're most likely setup to be running 5w-___ or 10w-___, since (safe to assume) most of the tolerances in your engine are still OE spec clearances.
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Off the shelf oils are so good these days that they are just fine. Stick with the weight of oil that the engine was machined to use. I personally like pennzoil after it was reformulated about 10 years ago, I had a 2004 Sierra I bought at 80k and sold at 190k. Around 185k I replaced the valve cover gaskets, the engine still looked new inside. There were only a couple of oil changes I did where I didn't use pennzoil. I personally like Mobil and Valvoline as well.
Tolerances are getting tighter and oils are getting thinner. I often see people run heavy weight oils in their LS hotrods, and when I ask why, the answer is always "cause it's a built motor"
"Built" has nothing to do with the viscosity you run, how it was built does.
Lastly, often times when say the rod or main bearings were set at looser tolerances for heavier oil, higher weight oil is recommended. Well what about all the other tolerances throughout the engine?
Long story short, you're most likely setup to be running 5w-___ or 10w-___, since (safe to assume) most of the tolerances in your engine are still OE spec clearances.
Tolerances are getting tighter and oils are getting thinner. I often see people run heavy weight oils in their LS hotrods, and when I ask why, the answer is always "cause it's a built motor"
"Built" has nothing to do with the viscosity you run, how it was built does.
Lastly, often times when say the rod or main bearings were set at looser tolerances for heavier oil, higher weight oil is recommended. Well what about all the other tolerances throughout the engine?
Long story short, you're most likely setup to be running 5w-___ or 10w-___, since (safe to assume) most of the tolerances in your engine are still OE spec clearances.
I am breaking in a motor and I used Rotella 15W-40 for the first 500 miles. Then I went to Pennzoil 5W-20 conventional for the next 2000 miles. I just finished talking to my engine maker and he recommended 10W-30 conventional. Should I drain the 5W-20 and put in 10W-30 or just stay with what I got? He also didn't recommend any specific brand but he did say that he was against Royal Purple, which I have used for years. I think I am going to start going with Valvoline VR1 racing 10W-30 synthetic when I get through this break in cycle.
What do you guys think?
What do you guys think?
Oh that crazy old blog resurfaces again. It is misleading. The oils that have the higher PSI ratings are of no benefit. GL-5 additives are added to raise the shock pressure. Gear lub has these additives to cushion ring and pinion shock. It is unnecessary for motor oil and is an oil producer marketing scheme.
Off the shelf oils are so good these days that they are just fine. Stick with the weight of oil that the engine was machined to use. I personally like pennzoil after it was reformulated about 10 years ago, I had a 2004 Sierra I bought at 80k and sold at 190k. Around 185k I replaced the valve cover gaskets, the engine still looked new inside. There were only a couple of oil changes I did where I didn't use pennzoil. I personally like Mobil and Valvoline as well.
Tolerances are getting tighter and oils are getting thinner. I often see people run heavy weight oils in their LS hotrods, and when I ask why, the answer is always "cause it's a built motor"
"Built" has nothing to do with the viscosity you run, how it was built does.
Lastly, often times when say the rod or main bearings were set at looser tolerances for heavier oil, higher weight oil is recommended. Well what about all the other tolerances throughout the engine?
Long story short, you're most likely setup to be running 5w-___ or 10w-___, since (safe to assume) most of the tolerances in your engine are still OE spec clearances.
Tolerances are getting tighter and oils are getting thinner. I often see people run heavy weight oils in their LS hotrods, and when I ask why, the answer is always "cause it's a built motor"
"Built" has nothing to do with the viscosity you run, how it was built does.
Lastly, often times when say the rod or main bearings were set at looser tolerances for heavier oil, higher weight oil is recommended. Well what about all the other tolerances throughout the engine?
Long story short, you're most likely setup to be running 5w-___ or 10w-___, since (safe to assume) most of the tolerances in your engine are still OE spec clearances.
Does it matter? I'm not sure which oil works better. When I use 10-30 the oil pressure at hot idle is closer to 35 lbs. When I use 15-40 Delo, my usual oil, it holds 37. The two pound difference tells me that the heavier oil flows just as well. If it held 42 lbs for instance, it would indicate a flow problem which I would consider. But it doesn't and I have peace of mind with the 15-40.
To the OP. Use straight weight 30W VR1. It holds its viscosity at 100* C (212 F) better than multi weight thirties and flows well too. Its also non synthetic and loaded with zinc and phosphorus, which is the main reason I use Diesel oil. The problem today is the new Ck-4 diesel is replacing the old CJ-4 and has only half the zinc and phosphorus level. When my supply of CJ-4 runs out, its back to VR1 30. Hope this helps.
Agreed except down here in Texas our viscosity recommendations are higher than in New York for example, and Australia is pretty close to the equator so it should be like Texas weather.
In other words, I would assume the recommendation for higher viscosity in Australia was due to high temps, rather than not needing to meet CAFE
Besides, since you obviously acknowledge the thinner oil will give better mpg, and mpg is a selling point, it wouldn't make much sense for them to run the higher viscosity and lose a couple of MPG points and potentially lose an edge on the competition.
But I've been wrong before, so I could be now too lol.
In other words, I would assume the recommendation for higher viscosity in Australia was due to high temps, rather than not needing to meet CAFE
Besides, since you obviously acknowledge the thinner oil will give better mpg, and mpg is a selling point, it wouldn't make much sense for them to run the higher viscosity and lose a couple of MPG points and potentially lose an edge on the competition.
But I've been wrong before, so I could be now too lol.
It’s an incredibly long read, if you start from the top. I’ve seen people in the past say the same thing you are saying, and I just don’t see it. Guy seems legit to me. Help me out here.
I am breaking in a motor and I used Rotella 15W-40 for the first 500 miles. Then I went to Pennzoil 5W-20 conventional for the next 2000 miles. I just finished talking to my engine maker and he recommended 10W-30 conventional. Should I drain the 5W-20 and put in 10W-30 or just stay with what I got? He also didn't recommend any specific brand but he did say that he was against Royal Purple, which I have used for years. I think I am going to start going with Valvoline VR1 racing 10W-30 synthetic when I get through this break in cycle.
What do you guys think?
What do you guys think?
A) "I said use 10w-30 because that's what the motor is set up to run. The 5w-20 is too thin and that's why the bearings spun. Warranty Denied."
B) "I said use 10w-30 because that's what the motor is set up to run. The Rotella 15w-40 tractor trailer oil is for diesel engines, has the wrong additive package for gas, it's too thick and that is why your motor had excessive wear at cold start up and ate itself. Warranty Denied."
C) "I said use 10w-30 because that's what the motor is set and you did exactly what I said do. Let's tear it down find out what's wrong and I will help you out."
I would rather lay the ground work for "C" in case an issue occurs. In the end it doesn't matter what we think it will be what the builder thinks.
BTW - PooterSS is right on the money with what he said.
Valvoline VR1 racing 10W-30 synthetic - sounds good to me
I like Mobile 1 synthetic & Penzoil Ultra synthetic too.
My 91 RS old 305 ran like new after 389,500 miles of mostly Mobile 1 synthetic and it didn't leak Held good oil pressure too.
Last edited by 99 Black Bird T/A; Aug 28, 2018 at 08:59 PM.
I do not have the proprietary formula for those oils, but I do remember being involved in a thread years ago where a retired oil engineer stated that the high numbers were due to GL additive. He stated it was a marketing scheme. Are you familiar with the NOACK test?? Where a steel bearing ball is coated in oil and spun while a metal plate is applied against it. Pressure is applied and measured, and the scarring left on the ball is too. Oils higher in GL additive do better. But the test results are skewed because the test does not reflect actual operating engine conditions.
But, it sure looks impressive to those seeing the test and who do not know. Motor oil is about TBN numbers, viscosity, moly, zinc, phosphorus levels, shearing, flowing, detergent levels, antacid protection and soforth caused by internal combustion, none of which is an issue for rear axles and differentials.