Oil for my di engine

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What 5w30 syn oil has the best noack numbers and also I was looking for an oil that doesn't shear down so much. It seems like most of the 5w30 oils shear down to a 5w20 a lot in di engines. I usually use qsud or Castrol syntec.
 
I ran PP 5w30 in my Turo DI mazda CX7 and have good UOAs using 6,000 mile oil change intervals. My oil did not shear down over the 6K miles. Ed
 
Originally Posted By: waltywalt
What 5w30 syn oil has the best noack numbers and also I was looking for an oil that doesn't shear down so much. It seems like most of the 5w30 oils shear down to a 5w20 a lot in di engines.

The reason is that most of these readily available 5w-30 oils are energy conserving, which means they are formulated on the lower end of the 30-grade range of viscosity. And so it doesn't take much for it to drop into the 20-grade territory.

If you start with an oil that's formulated as a heavy 30-grade, then you're less likely to shear so much that it'll drop to a 20-grade. Unfortunately, such oils are not energy conserving. Example of such oil with very low Noack: Mobil1 ESP 5w-30.
 
Originally Posted By: waltywalt
What 5w30 syn oil has the best noack numbers and also I was looking for an oil that doesn't shear down so much. It seems like most of the 5w30 oils shear down to a 5w20 a lot in di engines. I usually use qsud or Castrol syntec.


I have a question. Why are you so concerned about shearing?
 
Because I wanted to use a 5w30 and not a 5w20 to begin with. If I wanted to use a 20w I would of just started with it in the first place. Just personal preference I guess.
 
I have never got a uoa on the oil in this car but ive read on hear a lot about 5w30 oil shearing down to a 20w in a lot of di engines. I would guess its because of the fuel washing down but idk for sure.
 
Originally Posted By: waltywalt
I have never got a uoa on the oil in this car but ive read on hear a lot about 5w30 oil shearing down to a 20w in a lot of di engines. I would guess its because of the fuel washing down but idk for sure.

I think Dave's point was that it may not necessarily matter that your oil thinned to a 20-grade. Engine manufacturers are well aware of the potential fuel dilution, and specify oil grades accordingly.

Now, if you started with a 20-grade and it ended up thinning to a 10-grade, then that could have been a problem.
 
Originally Posted By: waltywalt
Because I wanted to use a 5w30 and not a 5w20 to begin with. If I wanted to use a 20w I would of just started with it in the first place. Just personal preference I guess.


OK. Does your manufacture recommend a 5W30? If so do you believe the engineers that have made this recommendation have factored in that a 5W30 will shear? If so testing was done on this engine design that it would be nearly impossible for you to replicate in everyday driving use and a 5W30 is robust enough to protect your engine for it's designed lifetime shearing and all.
 
Originally Posted By: dave1251
Originally Posted By: waltywalt
Because I wanted to use a 5w30 and not a 5w20 to begin with. If I wanted to use a 20w I would of just started with it in the first place. Just personal preference I guess.


OK. Does your manufacture recommend a 5W30? If so do you believe the engineers that have made this recommendation have factored in that a 5W30 will shear? If so testing was done on this engine design that it would be nearly impossible for you to replicate in everyday driving use and a 5W30 is robust enough to protect your engine for it's designed lifetime shearing and all.

With top notch thinking like that, we can just shut down all sections of BITOG except UOAs.
 
Oh really? Do you have purpose for posting this? Because your comment is very vague and it can be misinterpreted/interpreted into many directions.

Please explain.
 
Originally Posted By: waltywalt
What 5w30 syn oil has the best noack numbers and doesn't shear down so much.


Are you willing to go to boutique oils, or want to stick with readily available synthetics?

AMSoil HDD has 9% NOACK, and is very shear resistant. It's a diesel oil formulated for pre-2007 engines, so it's probably high SAPS.

RedLine 5w30 has 6% NOACK, and is very shear resistant. It is formulated for gasoline engines.
 
Originally Posted By: TTK
Originally Posted By: dave1251
Originally Posted By: waltywalt
Because I wanted to use a 5w30 and not a 5w20 to begin with. If I wanted to use a 20w I would of just started with it in the first place. Just personal preference I guess.


OK. Does your manufacture recommend a 5W30? If so do you believe the engineers that have made this recommendation have factored in that a 5W30 will shear? If so testing was done on this engine design that it would be nearly impossible for you to replicate in everyday driving use and a 5W30 is robust enough to protect your engine for it's designed lifetime shearing and all.

With top notch thinking like that, we can just shut down all sections of BITOG except UOAs.


LMAO
 
Originally Posted By: dave1251
I have a question. Why are you so concerned about shearing?


Because when oil shearing occurs, wear metals increase.

Contrary to popular belief, viscosity is a necessary element of lubricity.
 
Then why do you use a 10W30 in your Buick? The majority of UOA's show the GM 3.8 shear 10W30's into the 20 grade range.

Your nearly 15 year old engine should be on in last legs by your logic.
 
NAPA Synthetic (Valvoline SYNpower in drag) is only $3.49 a quart this month. It may be worth using it with conservative OCI's. At that price, it may be worth it.
 
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The car calls for 5w20 or 5w30 or 10w30 depending on outside temps. Now ofcourse they call for the 5w20 1st for fuel saving but Almost everyone on hear agrees on using a 5w30 over 5w20. The car is a Hyundai veloster 2012. No turbo but I do get a very distinct smell of fuel whenever I change my oil so I hope the 5w30 stands up better then the 5w20. I guess if the car calls for the lighter oil and 5w30 shears down to a 5w20 then its no so bad. Im just trying to get an oil that has a low noack number and doesn't shear a lot. Like I said I usually use qsud or Castrol syntec but im open to just about any oil. Ive used pu and pp. Ive used Valvoline syn. To be honest im no expert on oil. They all seemed fine to me considering I change the oil at 3,750miles anyway. The dealer said to change the oil at 4,000 miles and the car will be fine but when I look in the book for severe it says to change it at 3,750miles. I usually get my oil from advanced or autozone whenever they have the deals on the oil and filters. Just so happens that whenever im doing a change its usually when they have the deals on qsud or castrol syntec. Im just over thinking it I guess. Most people on hear say its a waste to change synthetic so early but im used to changing oils at 3000 miles anyways. This is my first DI engine so im trying to get as much info as I can. From what ive learned hear most Di engines have an issue with shearing and they also have had problems with carbon build up on the valves so I just went with synthetic from the start. And everyone seems to think that running synthetic and keeping the change intervals short takes those problems away. Only time will tell I guess.
 
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