RP 10w40 2006 STI 3,624mi

[addyguy]

M1 15W-50 would be fine, right down to below freezing. In reality, it is probably actually a 10W-50 oil; but that grade gets confused with MC oils, and the horrible multi-visc's of the 1970's (15,000-mile STP 10W-50, anyone? Or how about Shell 'Fire and Ice' 10W-50?) The 15W-50's pour-point is almost the same as its 10W oils...people here have reported using it as low as -20 w/o problems....

 

[d00df00d]

 Originally Posted By: JoeFromPA

you can see in your analysis that it sheared (within grade)

Actually it's definitely out of grade. 40 weight is 12.5 cSt and up, and his report indicates 11.84. There are 0w-30s that start higher than that.

 

[DARKSTI]

 Originally Posted By: addyguy

M1 15W-50 would be fine, right down to below freezing. In reality, it is probably actually a 10W-50 oil; but that grade gets confused with MC oils, and the horrible multi-visc's of the 1970's (15,000-mile STP 10W-50, anyone? Or how about Shell 'Fire and Ice' 10W-50?) The 15W-50's pour-point is almost the same as its 10W oils...people here have reported using it as low as -20 w/o problems....

I am also a little hesitant to use M1 as there are have been some problems with spun bearings using it, although it seems it to be mainly the 5w30 weight...

 

[d00df00d]

 Originally Posted By: DARKSTI

I am also a little hesitant to use M1 as there are have been some problems with spun bearings using it, although it seems it to be mainly the 5w30 weight...

Those claims are vapor. People beat the [censored] out of their cars and/or race them without the appropriate mods to prevent oil starvation, and their engines frag; then the engines are rebuilt stronger, the right mods are put in, and surprise surprise, no more problems. It just so happens that they were using Mobil 1 before (it's the most popular synthetic), and whatever shop they go to either uses dino oil or some boutique oil like Royal Purple, just out of habit -- and people conclude from this that it's the oil that made the difference. I can't say I'd recommend a 15w-50 personally, but there should be no problem with Mobil 1 in your Subie.

 

[JoeFromPA]

DARKSTI - Those fears about M1 focus on the M1 5w30 oil. Not 0w40 ( a good oil), 5w30 extended performance, 15w50, or any other variation.

 

[DARKSTI]

 Originally Posted By: d00df00d

 Originally Posted By: DARKSTI

I am also a little hesitant to use M1 as there are have been some problems with spun bearings using it, although it seems it to be mainly the 5w30 weight...

Those claims are vapor. People beat the [censored] out of their cars and/or race them without the appropriate mods to prevent oil starvation, and their engines frag; then the engines are rebuilt stronger, the right mods are put in, and surprise surprise, no more problems. It just so happens that they were using Mobil 1 before (it's the most popular synthetic), and whatever shop they go to either uses dino oil or some boutique oil like Royal Purple, just out of habit -- and people conclude from this that it's the oil that made the difference. I can't say I'd recommend a 15w-50 personally, but there should be no problem with Mobil 1 in your Subie.

 Originally Posted By: JoeFromPA

DARKSTI - Those fears about M1 focus on the M1 5w30 oil. Not 0w40 ( a good oil), 5w30 extended performance, 15w50, or any other variation.

Thanks for the info guys, I just may try it then :D I thought it was just the 5w30 so that makes the decision a little easier.

 

[DARKSTI]

Since they are the same price would RL 10w40,15w40, or 15w50 work just as well? Also, would gas mileage go down much more with the 15w50 vs 10w40? Just for the heck of it, what about RP 15w40? Since I do change my oil a bit earlier than most would it be worth trying that first since it slightly cheaper?

 

[d00df00d]

There should definitely be a fuel economy difference. The question is whether you'd notice, and you'll get answers either way on that. The only way to know for sure is to do a LOT of testing. You always want the thinnest oil that'll do the job. Start with the 10w-40 and see if that works for you.

 

[DARKSTI]

 Originally Posted By: d00df00d

There should definitely be a fuel economy difference. The question is whether you'd notice, and you'll get answers either way on that. The only way to know for sure is to do a LOT of testing. You always want the thinnest oil that'll do the job. Start with the 10w-40 and see if that works for you.

That's what I was thinking because I did notice when I switched to the RP 10w40 that my MPG when down just enough to notice although I think I may get some back when I replace the air filter tomorrow. Although I may be thinking weird that's also why I chose RP because I wanted a thicker but thinner oil if that makes any sense because of the temp swings and trying to find a balance with the gas mileage. That's also why I am curious about the RP 15w40 and RL 10w40, would there be a huge difference in shear/wear etc, is the RL worth the extra $2 or so?

 

[DARKSTI]

Also, is THIS the right M1?

 

[d00df00d]

Again, no way to tell unless you try. However, I think we can make a safe bet: - Royal Purple is known to shear sometimes - Red Line oils are known to be very shear stable in general - Red Line 10w-40 in particular is one of their stoutest oils I would definitely pay the extra $2 for Red Line. That amounts to, what, $10 a change?

 

[JoeFromPA]

That's the right Mobil One; you can find it for $22 for 5 quarts at Walmart (or very near that price). You will probably not notice a difference in MPG...it's not like an STI is known for getting a "rock solid"MPG every time it stops for fuel. It'll be your driving characteristics.

 

[DARKSTI]

 Originally Posted By: d00df00d

Again, no way to tell unless you try. However, I think we can make a safe bet: - Royal Purple is known to shear sometimes - Red Line oils are known to be very shear stable in general - Red Line 10w-40 in particular is one of their stoutest oils I would definitely pay the extra $2 for Red Line. That amounts to, what, $10 a change?

 Originally Posted By: JoeFromPA

That's the right Mobil One; you can find it for $22 for 5 quarts at Walmart (or very near that price). You will probably not notice a difference in MPG...it's not like an STI is known for getting a "rock solid"MPG every time it stops for fuel. It'll be your driving characteristics.

OK thanks again guys, I think I will try the RL 10w40 first then maybe the M1 :)

 

[bluesubie]

Wow, the RL sheared and the RP (no surprise) sheared. Are you running any mods? RonJitsu (I think that's his screen name here) and I are running nearly 8k intervals with Amsoil (and me previously with GC). There's a very good uoa here somewhere from a protuned Stage II STI running RL 10W-40. I would search but it would take too long. -Dennis

 

[DARKSTI]

 Originally Posted By: bluesubie

Wow, the RL sheared and the RP (no surprise) sheared. Are you running any mods? RonJitsu (I think that's his screen name here) and I are running nearly 8k intervals with Amsoil (and me previously with GC). There's a very good uoa here somewhere from a protuned Stage II STI running RL 10W-40. I would search but it would take too long. -Dennis

No engine mods, just stock. Any idea why the RL would shear also? Is it just because I am a little heavy with the throttle? I thought about Amsoil but I don't want to have order online and with me being a few minutes from Summit I can get RL without ordering online so I wanted to try that first.

 

[d00df00d]

Fuel dilution.

 

[ARCOgraphite]

 Originally Posted By: DARKSTI

... but it seems to run amazingly smoother and quieter with RP 10w40, although it's probably a placebo effect.

If its seems to run better it probabaly is in my book, YOU are the guy to please in this game, not us