20w-50 vs. 15w-40

[uconn1150]

I have a '93 Civic (140,000) & a '87 Ramcharger (150,000) and I live in the desert of West Texas. I have always run 20w-50 and never had a problem. I'm AutoRXing at present, and am curious how Schaeffer's 15w-40 or DELO 15w-40 (or M1 15w-50 if I go full syn) will perform as compared to the 20w-50 I currently use. The temps in the summer easily reach 115F and with AC on MAX in traffic, I need all the protection/performance I can get. Thanks for all of the opinions & suggestions!

[ March 25, 2003, 06:56 PM: Message edited by: uconn1150 ]

 

[Patman]

My vote goes to Schaeffer 15w40. Used oil reports show it to be just as good, if not better than Mobil 1, but at a lower price.

 

[Al]

I agree with Patman...but I would go with any 40 wt. over the 50 wt. Certainly the 15W-40 Mobil Delvac 1300 would be a great choice as would the Chevron Delo 400

 

[uconn1150]

Thanks Guys for the help! But here's another question...what are the upper bounds (temp wise) for 40 as opposed to 50? Why wouldn't I want 50 instead of 40? Is there that much difference between the two?

I've decided on 15w-40 for next winter but need some more info to use it year round...I really love my 20w-50!

Thanks Again!

 

[Eiron]

What are your intervals on the un-named 20W-50, & would you change those intervals if you switched to Schaeffer's or Mobil 1?

 

[rugerman1]

uconn1150 ,
How many miles have you put on these vehicles using 20w-50?Any consumption?IMO,ambient temperatures are irrelevant if the cooling system is adequate.What coolant temperatures do you see in the hottest weather? My primary concern with 20w-50 is in cold weather.

Mark

 

[uconn1150]

quote:

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Originally posted by Greg Netzner:
What are your intervals on the un-named 20W-50, & would you change those intervals if you switched to Schaeffer's or Mobil 1?

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I've used GTX, Chevron Supreme, and now SuperTech...they all have been changed out at about 3K mi. I would change the intevals to 4K for the Schaeffers & 5K for the Mobil 1.

 

[Norm Olt]

Just an opinion: my humble one, actually!

Read the back of a dino 20W-50 oil.

Read the back of a 15W-40 "Fleet" oil.

All those diesel-specification hoops the oil mfg. has to jump through must mean something! These oils PROBABLY are formulated from better base stocks, have better additive packages, better cleaning, temp control, etc. than the "regular" car oils. This PROBABLY applies across the entire cross-section of the various manufacturers. I'm not sure this applies in EVERY case, but PROBABLY!

I don't think you can go wrong with Pennzoil LongLife, Delo, Delvac, Rotella, or +$ to Amsoil, M1, Schaeffers, etc. I use this kind of oil in my wife's Mercedes 420SEL year-round because we don't see the bitter cold in the winter. When it is under a $ how can you loose?

Try one: see what your temp gauges say. I don't see the average 20W-50 car oil outperforming a fleet oil in your situation IMHO

 

[uconn1150]

quote:

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Originally posted by rugerman1:
uconn1150 ,
How many miles have you put on these vehicles using 20w-50?Any consumption?IMO,ambient temperatures are irrelevant if the cooling system is adequate.What coolant temperatures do you see in the hottest weather? My primary concern with 20w-50 is in cold weather.

Mark

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I've only put 15K mi, on the Honda and I just got the RC. On my '90 Hyundai, I went 160K mi on strictly 20w-50. The Hyundai was totaled, but the engine was still running very well!

As far as the cooling system comment, I don't think the engineers in the US worry too much about 115 temps (here) 125+ in Phoenix or worse I think, 95+temps in Houston w/70% humidity. Take having your AC cranked and getting stuck in traffic and I think temps begin to have an effect. I've read many posts here from ppl in Australia and then run the higher grades. I think the US is just brainwashing us on the thinner grades for fuel efficiency. I don't think oil would affect FE more than 3-5% at most. I'd rather have the protection.

[ March 26, 2003, 12:17 PM: Message edited by: uconn1150 ]