Switch Saturn with 150k on cheap 10W40?

[bob555]

Friend's 1993 Saturn (DOHC) has been on cheap 10W40 dino for all of its 150k miles. This summer, he asked whether his dad's insistance on 10W40 was a good idea since the engine specs 5W30 on the filler.

So, for the summer, I had him use Delvac 15W40 to sort of put off any major changes in viscosity.

Would it be ok to switch back to lower viscosity oils? What would be a good oil to try? Oil pressure takes a bit long to come up in the winter with 10W40.

As a side note, I already convinced him to switch away from the $7 white can frams to AC filters.

 

[Flimflam]

Bob, the Saturn is an oil-burning beast. So you are better off using a slightly thicker oil. Using 40-weight was a wise decision. Stick with 40-weight.

"If something works, don't mess with it."

 

[eljefino]

Ran Xw40 in two saturn SOHCs this summer. Liked Pennzoil LL 15w40 over Superflo 10w40 (but who wouldn't?

)

 

[bob555]

Yeah, I think it runs fine on the 15W40 Delvac, actually quite a bit smoother than on Brand "X" 10w40...the problem is winter.

What about running Rotella Syn 5W40 in the winter? Or which dino 10W40 has the best cold temp properties?

 

[ToyotaNSaturn]

Bob, I've run M1 15w-50, Syntec 5w-50, PZ LL 15w-40 and Delo 400...all with good results in my 96 SL2. The owner's manual only states 5w/10w30. A CAFE only thing for sure. For colder weather, why not just add a quart of 5w-30 Chevron Havoline with Delo 400? ...or a qt of PZ 5w-30 with LL 15w-40? Unless your starts are consitently below zero, the 15w-40 of your choice will suit your needs just fine.

 

[bob555]

Thanks for the suggestions. I'm torn between thinning some 15W40 with 5W30 or 5W20 or using Rotella Syn.

Crappy (read Coastal and cheaper) 10W40 definitely took a *long* time to build pressure at 10 degrees.

The car probably sees maybe 30 days below zero in the winter, a 50/50 split between highway and city driving.

 

[Patman]

quote:

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Would it be ok to switch back to lower viscosity oils? What would be a good oil to try?

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Another good choice would be a 10w30 high mileage oil as many of them are almost 10w40 oils already.

 

[Gary Allan]

quote:

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I'm torn between thinning some 15W40 with 5W30 or 5W20 or using Rotella Syn.

Crappy (read Coastal and cheaper) 10W40 definitely took a *long* time to build pressure at 10 degrees.

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Okay ..so either go with the Rotella synth ..or go with a 5w-30 and just top up any consumption with a heavy weight. Before you know it ..winter's over!!

I mean ..how long does this car go between changes? Is it typically seasonal?

 

[ToyotaNSaturn]

With that many below zero days, M1 0w-40 if you're considering true synthetics, or a mix of Syntec 5w-50 and Syntec Blend 5w-30. I tried that mix too, and it works just fine. Since the Castrol products (save for GC) aren't true synthetics, you don't have to worry about about selling your friend on the whole "going synthetic" thing.

 

[Sin City]

If you can get Rotella T 5W-40 on sale then that is the way to go. If you can find Shell Rotella T, Chevron Delo, or Pennzoil Long Life 10W-30 those oils will also be a good selection and their viscosities are very close to a 10W-40.

[ September 16, 2004, 12:01 AM: Message edited by: Sin City ]

 

[nascarnation]

If he's feeling prosperous, I'd recommend Mobil 1 0W40. Our 110,000 mile 97 SC1 went from 1000mi/qt on 5W30 dino to 3000mi/pint on the M1.
This is definitely not cost effective, but on a car my daughter has at college and doesn't get checked like it should, it's cheap insurance.

 

[Neil Womack]

Bob

If you've run this car on 10w-40 for 100k I doubt your going to hurt it now with a 10w-40 or 15w-40 oil. Of course going to a lower weight won't hurt either. However, oil consumption might rise.

My wifes 96 SL-1 has run Schaeffer's 15w-40 for the last 36k of its 136k life. No cold start problems down to 10*f and half the consumption rate compared to the 10w-30 previously used.

Take a look at the cold flow numbers on the Schaeffer's they are better than any of the other conventional 15w-40 oils.

Penn LL Schaeffer's
15w-40 15w-40

Mini-rotary
Viscosity
ASTM D4684 23,000 14,368

Not all 15w-40s are the same on the test bench.

[ September 16, 2004, 06:07 PM: Message edited by: Neil Womack ]