So Patman, you are saying that a 0W30 Castrol has a better viscosity curve than a 10W30 Mobil 1? I am sceptical that a 0w30 oil can provide protection at high temperatures - if it does, it must be some amazing stuff. What about a 15W40 Mobil 1?

 

The OWO1 oil was designed for very cold starts in cold climates. It is true some all out race applications use very thin oil and do see horsepower gains but at the exspense of very frequent rebuilds. Many of the superstock guys play with this trick and some even run with as little as a few quarts total in the engine.

Someone posted that the Mobile 5W30 was to thin and would cause excessive wear on the bearings under hard use. I would have to disagree with that statement because I have used Mobil 5W30 in my engine since the car was new. After the engine was broken in and the rings seated I made the switch to Mobile around 7000 miles and ever since its been Mobile 5W30 synthetic. I don't know what would be considered hard use but at around 3000 miles on the car the motor was pulled out reworked and back in as a 383ci with N20. I beat the **** out of this engine for years and went thru over 50 bottles of nitrous either street racing or having fun not to mention driving the car on business trips. At 38,000 miles the engine was pulled apart and I was amazed at how well the rods,bearings,cam looked.

I would have no problem what so ever using it again in my driver. Would I use Redline oil? Yes if it was cheaper but for a daily driver I would not pay $8.00 a quart. I think for the difference in cost you will not see any advantage either way by paying more for Redline vs Mobile Synt.

One oil of interest two look at is Royal Purple. They have a specific oil designed and proven to resiste detonation with nitrous use where other oils have such problems.

With drag application I would recommend and I have used Valvolin VR RACE OIL. Very good also.

One last word leave on, I just switched from standard fosile oil in my 2003 Tahoe Z71 to Mobil 1 synth 5W30 and just after the first oil change I seen a 2 to 3mpg better gas milage!

I think that is some outstanding results from just changing oil. Buy the Mobile 1!

 

alright, i've got the memory retention of a goldfish, so break it down to me.

with a motor that has 5,000 miles on it, what oil should i use on it? i'm due for an oil change, so now's the time for action.

oh yeah, so far, i've been using 10-30 oil.

 

Thanks Patman! I'll track some down this weekend..

 

With Redline you would do fine with their 5w30 or 10w30, since this oil has an extremely good HTHS for a 30wt oil. Their HTHS numbers are comparable to many 40wts.

 

Mobil doesn't make a 15w40, they have a 15w50 and a 0w40 though. Their 15w50 is too thick for the LT1, but the 0w40 would be ok, although their HTHS number isn't super impressive for a 40wt oil, it's about 1 point lower than most 40wts. Redline 10w30 has a higher HTHS than M1 0w40 for instance. Redline 5w30 and 10w30 have an HTHS of 3.8, M1 0w40 is 3.6, M1 5w30 and 10w30 are only around 3.1. Amsoil 10w30 and 5w30 are 3.5. The German 0w30 Castrol is 3.6.

I know a lot of people are skeptical that a 0w30 oil can provide high temperature protection, but with the higher HTHS and thicker viscosity at 100c compared to Mobil 1 10w30, it's obvious this oil can handle the heat. And I've seen first hand that even in 5500 miles it doesn't thin out. I can't wait to see how it performs in my own car, I'm confident it will do very well. That's what I love about doing oil analysis on my oil, it shows me for sure how an oil is performing.

 

Fuel economy is a big reason GM specifies 5w30 on all it's cars, plain and simple. Although I'm not necessarily saying 5w30 is too thin, just that Mobil 1 5w30 is closer to being a 5w20, that's all, so I find it's too thin. If you're using Redline or Amsoil's 5w30, both of them are closer to being 5w40s.

 

Patman, thanks for the advice. I have noticed that when I recently switched from Castrol 10W-30 to Mobil 1 10W-30 my car started burning oil. It doesn't make sense to me. I want to try a different oil that may be a little thicker. My car doesn't smell like it is burns oil so I am thinking I may have to replace the valve seals. Do you think I would be better off with a 5W-30 or 10W-30. Thanks again for the help.

 

i did mobil 1 in my car... an i changed it, more often than not, every 2500miles.... you could shave in my heads at 63k....


oil pressure was fine... no leaks... and i waited for it to go on sale at kmart at $4 a quart...

 

You could always go with the 10w30 in the summer, and 5w30 in the winter.

 

Just a thought on the higher the weight the better theory........

I think most of us would be suprised to see what weights these guys run in 800hp, $60,000+ motors.

Bret

 

We use Torco 70w in our blown alcohol 572 chevy if you want something thick!

 

So really the rating on the oil itself isn't really as "useful" as thought?? What really matters is the HTHS as to compared wt vs. wt?

 

HTHS is an important factor yes, but at the same time, a 20w50 oil has an extremely high HTHS but if you ran this oil it would be too thick. But Redline's 5w30 has a much higher HTHS than Mobil 1 5w30 does. So it's part of the reason this oil is better. Amsoil and Redline are extremely good, it's hard to choose which one is better actually.


Best thing to do in order to try and find the best oil for your situation is to see how the wear numbers look on an oil analysis report for your actual oil.