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Motor Oil: 5w-30w vs. 10w-40w

07/28/2009 4:25 PM

specifically for Andy Germany please.

Tks your informative and rational posts,

I have recently bought a saab 9-5 turbo (8/2001) @125,000 klms.

I live 125 klms from nearest Australian big town and dealership (which is an add-on to an Holden outlet anyway). My usual mechanic replaced the 5w- 30w mobil with 10w-40w (US brand 'Neo').

I had asked him to stick to 5w-30w (and he said he would, but didn't!)

I requested that, because reviews of the 9-5 turbo mentioned earlier models had an oil pooling problem. It was inferred this has since been sorted out.

But I wonder, was that by using the 5w? and, has my mech. put my vehicle at any risk?

Also, are there any benefits to off-set my worries?

Or should I be carefully flogging my way over to the dealership for the manuf. recommended 5w-30w?

I'd greatly appreciate hearing from you as I'm 'going the other way' oil-wise to the original posts Dad.

Thanks

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#1

Re: Motor Oil: 5w-30w vs. 10w-40w

07/28/2009 8:33 PM

Personally, I would have the oil flushed and changed to the 5W-30 as the lubricating properties of the 10W-40 are generally less satisfactory for a turbo engine. With some 70K miles on the automobile it is not a good idea to decrease the lubrication on the engine if you want to maximize its life which I assume you want to do.

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#2

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 1:17 AM

To settle your concern check the API code recommended for the vehicle, this being correct will assure proper lubricity is maintained during operation.

Be sure to use the full synthetic lubricant recommended by SAAB:

Petrol engine (turbo): Saab Turbo engine oil or engine oil complying with API SH/SJ and ACEA A3-98.

We advise against the use of additional additives.

Viscosity (turbo):

SAE 5W-30 or 5W-40. These oils must be fully synthetic or synthetic-based.

At constant temperatures in tropical climates, use 10W-50 or 15W-50.

If 5W oils are used, they must be of fully-synthetic or synthetic-based type.

Petrol engine (aspirating engine): The basic recommendation is Saab Turbo engine oil as above but mineral-based oil complying with at least ACEA A2-98 is acceptable.

Viscosity (aspirating engine):

SAE 10W-30 or 10W-40. At constant temperatures of -20°C (-4°F) or below, use 5W-30 or 5W-40. These must then be fully synthetic or synthetic-based.

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#3

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 9:53 AM

Dudley,

I have a 1999 Saab 9.3. When the oil sending unit started send oil warning I did a fair amount of research on line about oil and Saabs. The one thing that was very prevalant was an issue with oils sludge build up that eventually caused engine siezure. After reading that I flushed the engine with a flush 3 times. I started using synthetic based oil as well. To date I have 153,000+ miles and still runnning.

So Flush the engine oil and start using synthetic

Bob

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#4

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 11:17 AM

I had an old timer mechanic tell me to just use 50w oil. He said if your engine leaks it will leak less on 50w and that he's always used 50w on all his cars and has never had a problem caused by the oil.

I'm just throwing that out there as thought. I know oil performance is affected by the temperatures of the region the automobile is operating in.

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#5
In reply to #4

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 12:27 PM

I use 40 and 50 weight oils in the performance engines I build. I would never recommend using 50 weight in a stock engine.

The clearances are much tighter in current production engines, and some engines like the Hemi in my Dodge truck shut down cylinders by bleeding off the lifters, and can malfunction if you use a heavier weight oil.

I'm not particularly comfortable with 5-20 oil but until I buy a service manual I'm going to stick with the manufacturers recommendation. Even then the heaviest I would go would be a 5-30.

As far as 10-40 oil it is the one viscosity range oil that I would not use, at least non-synthetic. This particular oil requires a thin base stock, and for some reason the viscosity improvers are more prone to break down in this range. Many years ago this prompted 15-40 oil to be the preference in heavy-duty applications. I can't find any current literature so I'm going to assume the problem still remains valid.

Even though the viscosity range is just as wide in 20-50 the base stock is thicker and the oil is much more durable.

You can't go wrong sticking to the manufacturers recommendation, although you might do a little better at least in my opinion with a slightly heavier maximum viscosity i.e.5-30 versus 5-20.

One thing's for sure putting an oil that is thick in a tight engine will do nothing but cause problems and accelerate engine wear.

50 weight is used in aircraft engines and high-performance engines. The big difference is these engines are designed with clearances that this oil is suited for.

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#10
In reply to #5

Re: Motor Oil: 5w-30w vs. 10w-40w

07/30/2009 2:25 PM

GA though I encourage others to become aware of and use MIL/API ratings when considering deviation from recommended lubricants.

A reasonable understanding of the objectives of using MIL/API rating can keep one from snapping their pencil

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#11
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Re: Motor Oil: 5w-30w vs. 10w-40w

07/30/2009 2:39 PM

GA though I encourage others to become aware of and use MIL/API ratings when considering deviation from recommended lubricants.

A reasonable understanding of the objectives of using MIL/API rating can keep one from snapping their pencil

www.tnk-oil.ru/doc/doc.asp?obj=70095

http://www.carbibles.com/engineoil_bible.html

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#12
In reply to #11

Re: Motor Oil: 5w-30w vs. 10w-40w

07/31/2009 4:38 AM

Hello bwire:

I like the charts, I only have one problem with them. Why do all the gradings I remember end with the phrase obsolete ? Are you insinuating something.

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#6

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 1:49 PM

Always use the manufacturers suggested oil.

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#7

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 2:17 PM

I did some follow-up research and contacted Amsoil. Their representative directed me to a website that has considerable information and flowcharts that may be of interest to you. The chart I was looking at is the fourth one from the left on the top row. There is quite a bit of information available in these charts.

http://images.google.com/images?gbv=2&hl=en&ei=3o5wSs-DFJL8sgO1y43uCA&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=viscosity+chart&spell=1

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#8
In reply to #7

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 3:17 PM

Thanks YW. I checked the chart and feel I understand more. Thanks also to all others who commented and whose suggestions, I considered carefully.

I'm beginning to feel, given the age of my vehicle and the imminent approach of spring/summer here in Australia, that the top synthetic 10w - 40w by 'Neo Racing' actually used, will be o.k.

An interesting aspect of this issue, which promulgated my specific enquiry, is that the Saab model - handbook says words to the effect "When you start up don't sit there warming up the engine - move straight off " which is not explained. Now, on leaving home on a 'cold' engine - it having stood overnight at least 8- 10 hours, I go uphill on a 1 in 6 straight away (albeit for 150mtrs only) and I deliberately rev only enough to get me up there without engaging the turbo. My rationale being: "this engine is cold and potentially under-lubricated at this point -so what good could it possibly do to put a heavy load on it?" (It's only a 2.3 litre and with electric seats et al weighs in heavily.)

On reading this through I realize I should have made enquiry of Saab, but having got this far I throw it open to you good folk to consider and advise in the hope that the subject matter may thereby edify many others, beyond just myself.

Thanks.

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#9

Re: Motor Oil: 5w-30w vs. 10w-40w

07/29/2009 5:21 PM

Usually in the original handbook, there is a table of oil type against temperature of where you live and I suggest you follow this exactly.....

If you live in a relatively hot part of Australia for example, the 10W 40 may be great, but vever use a heavier oil than you need for the temps where you live.

I really like Longlife 3, it has worked great for me for the last couple of cars.....

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