Currently using Mobil 15w50 Performance.. overkill ?

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5abi6r

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Well i did ask before about what oil to use in my 388 LT4. What i wanted to ask about is that even after some aggressive driving and high rpm cruising (usually cruise in 4th at 6500 or so on the highway), the oil temp doesn't seem to get warm at all. On my display readout it usually stays below the 1/4 mark. Is this oil too thick and/or pulling too much heat out to even work good ? I do have a High volume pump and a 6.5 L canton pan. I was thinking all the extra capacity in the pan was keeping things very cool.

Planning on using an Amsoil synthetic, anyt input on the best oil for my app would be appreciated.

Untuned (spent the day pulling fuel out because the sniffer in the muffler was in a bad location away from exhaust flow), and with an overdrive ATI damper spinning my accessories 12% faster than stock :/ (why do they make an overdrive damper grr.. underdrive is on its way this week)). Adding that my motor spins 2100 rpm higher than stock my accessories are probably spinning 25-30% faster than stock. Im thinking even the 50 wt oil i have in it is costing me some hp.

Still, she put out 456 rwhp @6850 rpm and still making over 440 rwhp @7800 on a Mustang Dyno. Tq was 397 rwtq @ 5800 rpm. After tuning and getting an underdrive damper on it Im sure the numbers will increase.

Any thoughts on oil would be appreciated
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Sounds like a good canidate for a 5/40 to me.

Cold weather protection, and still prevent huge consumption once you warm up the engine.
 
You're in Canada - Maybe Esso XD-3 0W-40? Can get it at most Wal-Marts....0W-30 might even suffice, very shear-stable.....
 
I didnt mean I always cruise at those rpms, thats usually in 3rd just to make noise and to listen to the beautiful sound going under overpasses. 6th gear at 120 km/hr is about 1700 rpm.

Do you guys think a 30 wt oil would be too thin ? I don't drive the car in the winter and its always parked in an insulated garage.

I went with Mobil 1 because the builder said to stick with mobil but I don't think he has a clue as to what viscosity vs clearances etc. I chose the 15w50 (or is it 10w50 - not sure) because it says 'Performance Driving' right on it.

i also know this will sound stupid, but I don't think I would ever put an esso branded oil in my car ! I always thought those were cheapo oils that gas stations leave stacked out by the pumps :/

Im considering an Amsoil, Redline or Royal purple full synthetic that will be thinner and still provide High rpm protection.
 
I would tend to think that a 50 weight is a tad thick as well. A good synthetic 40 weight (xW40) oil should do the trick and strike a good balance.

You should do a UOA on the 15W50 after you remove it and see how it did. I would then do a UOA on the next oil that you choose to compare and see which one did better (as long as your driving and external factors are as similar as possible).
 
No idea what a UOA is or how i would do one around here. Looking at the letters I'm guessing 'Used Oil Analysis'. What should I be looking for if I do one ?

I think I will go with a 40 wt. this ketchup is coming out tommorow !
 
I notice it says Diesel FI engines, Superchargers and Turbo chargers. All are probably producing much more heat than I am even though I am revving high. I 'm definitely convinced it is too thick.
 
Yes, UOA is used oil analysis. Blackstone labs is a good company, and the will send you a free sampling bottle with purchase of an analysis. You can purchase online at www.blackstone-labs.com

You can also purchase a kit through Oil Analyzer's Inc (OAI Testing) www.oaitesting.com - same deal.

I think UOA is well worth the money to have piece of mind that the oil you choose is providing the best protection for your engine. It also provides info as to whether or not your engine is operating as designed, or if there's an iminent problem or dirt ingestion.

As a side note, I don't think the 5W50 is so bad that you need to get rid of it right away. I'm sure it's more than adequate until the next oil change (or for a bit longer anyway). If you do decide to do a before and after UOA of the 5W50 and of the other oil of your choice, make sure the km interval is the same.


EDIT: A thicker oil actually produces more heat than a thinner oil. This is because a thicker oil has more internal friction (intrafluid friction) than a thin oil, and thus more friction equals more heat production within the oil.
 
quote:
Originally posted by ebaker:
What's your hot idle oil pressure?
Click to expand...
Oil pressure when cold almost pins the stock guage at High. When it warms up it drops just a touch. When fully hot I'd say its still at 75% or so.

I know when i just bought the car the pressure would be at half and actually seemingly low at about 15% when Hot. it was almost at the red zone. it stayed that way throughout the stock motors life (8 years).

Again I do have a high volume Melling pump that is probably the source of high pressures.
 
Aside from any valve train requirements for viscosity, your high volume pump is costing you flow. Whenever you're "pegged", the pump is in relief. The higher the visc, the more you're going to be in pump relief. You want to pass as much of the high volume flow of the oil pump while having a viscosity that will keep your valve train wear in check due to (no doubt) higher rate valve springs.

Now you can throw all this out the window if you're someone who's going to refresh the engine every few years anyway. It all depends on how you're going to spend your diposible cash (which is, at this time, substantial).

Pull a mileage figure out of your behind on how often you're going to change your oil. Do a UOA on the current fill. Replace it with your 0w-40 or 5w-40 of choice. Same mileage ..do a UOA. If all is good, step down to either a 10w-30 or a 5w/0w-30 and do the same thing. If you don't see any evidence of increased valve train wear ..I'd stop there and be happy.

I would think that your next stops are either the XD-3 synth line ..or maybe the Rotella 0w-40. They're HDEOs and the XD offerings are a bargain according to your fellow Canadians.
 
He's in a pickle, Mitch. He's got a high volume oil pump. To meet your spec's ..he might have to go to a 5w-20 or 0w-20. That would probably wreak havoc with his cam. He can only step down so far in visc ..at least without some massive dosing of some AW additive ..maybe even not then
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Thanks so much for the input. As for how long I'm leaving the oil in is probably 2-3k at the most. As you said (Gary Allan) I'm just worried to step down too far and not have a thick enough viscosity to protect the valvetrain. it is a solid roller and even though the lift isn't very large (.560) The spring pressures are high to handle the rpms (7950 max).

if I may ask what should I be looking for when it comes to UOA ? Also what is the XD-3 synth line ? I was thinking to go with a Redline 10w40, any thoughts on redline?
 
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