I'm stuck on the simple stuff: Which oil to buy?

[mazda6Lvr]

Hi. Great forum. I've been a lurker forever it seems, and only recently decided to sign up as a member. I've got some pressing questions that I need to get some answers to, and therefore any advice fellow BITOG members might have will be invaluable:

First of all, a bit of background:

I'm from Vancouver, Canada and I own a 2004 Mazda6. The car's been serviced and had all oil changes done by the dealer for the past 70K kms. The dealer fill is 5w-20 semi-synthetic. I'm now finally ready to cut the umbilical and start doing my own oil changes.

Yes, I plan on using fully synthetic.

However, two things really block my path at the moment:

1. Limited availability of good synthetic oils in Canada.
2. Price. Good oils cost WAY too much.

Just to explain something for any US readers:

We don't have Pep Boys or Autozone in Canada. We have Canadian Tire (a combined automotive, household goods and sporting good superstore of sorts), Walmart, and small independent shops. That's it.

I'd love to run GC. Problem is that GC is so uncommon in Canada its not funny. I found out from someone that GC can be found at Canadian Tire (CT). Well, I've searched all the CT's in the immediate area (about 4 stores so far) and I haven't found any that carry the stuff. When I lived in Toronto, I never found GC on the shelves there either so obviously GC is only available at select stores throughout the country.

So, lets say I give up on the GC dream and instead go with regular USA-made Castrol Syntec. Regular Syntec goes for $8.99 for a 1 liter bottle of 5w-20 at CT. I have yet to find a CT store that sell regular 5w-20 Syntec in the 4.4 liter format. They do, however, sell 5w-30 in the 4.4 liter format but that's not the recommended weight for my engine.

So, if I were to buy 5 x 1 liter bottles of 5w-20 Syntec, I'd be looking at $50 for the oil alone (with taxes) and I'd still need to pay for the oil filter.

Same story for M1. M1, however, isn't fully synthetic anymore... but lets say that its my third choice of oil after GC and regular Syntec. M1 5w-20 in a 4.4 bottle has always had a price tag of $39 at CT since time immemorial. They never put 5w-20 on sale... its always 5w-30 that on sale for $31. Even Walmart and other stores in the area have M1 5w-30 on sale for $32-ish for the 4.4 liter bottle... but never 5w-20.

Redline? Too expensive! If I'm complaining about $8.99 a bottle, then I certainly am not in the market for $12.99 a bottle. Same goes for Royal Purple.

The only thing left is Quaker State Advanced Fully Synthetic and Canadian Tire's own brand: Motomaster Formula-1 Gold Fully Synthetic. Quaker State costs about $34 for a 4.4 liter jug.

But all this is based on the assumption that I've GOT to run 5w-20. If I ran 5w-30 from now, then I'd be saving a bit of money. Besides, if I ever find GC, it only comes on 0w-30 anyways...

So... ideas/opinions?

Should I start using Xw-30 oils that tend to cost less or should I go with a cheaper brand of synthetic like Quaker State Advanced?

Also, what's the effect of running 5w-30 in an engine that the manufacturer states should only take 5w-20? Since the oil is thicker, will that have an effect on the oil seals? I've heard from some that the engine can potentially feel more sluggish with the heavier oil.

Any advice will be much appreciated.

 

[Johnny]

First of all

to BITOG.

Personally I would not have a problem using 5W30 in your Mazda. I put 5W30 in one of my Honda's to see what would happen, and nothing happened. I cannot even tell a difference in gas mileage.

All of the brands you mentioned are good products. So, if I were you, I would pick my favorite brand in a 5W30 and go for it.

Hope that helps.

 

[Rodbuckler]

Most definitely stick with the 5W-20's or 0W-20's if that is what your engine was set up to use. These 20 weight oils are excellent. An engine set up for 20 weight oil will generally pump a large volume of oil to the bottom end, and have a proper amount of oil metered to the top-end. You don't want to arbitrarily go thicker. And Eurospec 30's like Syntec 0W-30 are WAY thicker than the 20 weights at all temps.

Try any of the jugs of top-shelf full synthetic 5W-20 like the Q advanced or other. They will do nicely in your engine out to 10-12km OCI's since your engine is still fresh.

 

[TallPaul]

I understand Maxlife is available in 5w20 now, though I haven't seen it in the stores yet. Maxlife would be a great choice for your car. Actually a good choice for any car, new or old.

 

[Merkava_4]

Yeah Maxlife 5W-20 would be the hot ticket if you can locate some.

What about Motorcraft 5W-20, can you get some up there?

 

[Blue99]

Quote:

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An engine set up for 20 weight oil will generally pump a large volume of oil to the bottom end, and have a proper amount of oil metered to the top-end. You don't want to arbitrarily go thicker.

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Well, that kinda sounds like a nice statement!

So what happens, based on the above theory, when a typical 5W-20 is run at 45C(113F) degrees, and the oil is about 40 cSt, a far cry from the 8.5 cSt that we commonly think about when a 20 weight oil is discussed.

How does an engine "set up for a 20 weight", handle a heavier viscosity, 40 cSt oil?

Hint - The conditions I described are from Stage 5 in the ILSAC GF-4 Sequence VIB fuel economy test.

 

[Rodbuckler]

How does an engine "set up for a 20 weight", handle a heavier viscosity, 40 cSt oil?

It never has to. The 20 weight oil never behaves like the 40 weight oil in close quarters even though the kinematic viscosity might indicate that the two should behave the same. Behavior in the engine is radically different between the two oils at all temps.

 

[coffee]

I'm the broken record poster but I'll say it again

go with Motorcraft 5w20 Syn Blend. It is cheap at Wal-Mart and a wonderful oil!

 

[Blue99]

Quote:

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The 20 weight oil never behaves like the 40 weight oil...

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I never mentioned a 40 weight oil, which is defined by the SAE J300 chart as 12.5 to 16.3 cSt at 100C.

I was referring to a typical 5W-20 oil which is 40 cSt viscosity at 45C.

How does this theoretical "set-up for 20 weight engine" handle 40 cSt?

 

[Rodbuckler]

It would handle it like a dream come true. On the other hand if it were a 40 weight oil at 40cSt at some particular temperature, the engine would labor badly.

 

[Blue99]

Lets go back to Viscosity 101.

Motor oil viscosity is very temperature dependant.

A 5W-20, 5W-30 & 10W-30 are all in the 100 cSt to 150 cSt range at room temperature.

When the engine starts-up on a 72 degree day & goes thru the 3-10 minute warm-up stage, the motor oil slowly drops in viscosity from the 100+ cSt range to the final full operating temp of 100C,(212F), which is about 10 cSt for a 30 weight & 8.5 cSt for a 20 weight.

Only at the 100C temp range, is the oil a "20 weight", a "30 weight" etc.

So, the typical engine is required to operate on a broad range of oil viscosity thickness.

Now, an engine operating at high rpm, generally demands about 10 psi oil pressure per 1000 rpm, such as a high load, racing situation. This is were the 20 weight or 30 weight oil viscosity and bearing clearances becomes critical.

 

[Patman]

Quote:

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When I lived in Toronto, I never found GC on the shelves there either so obviously GC is only available at select stores throughout the country.

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That's odd because every CT and Walmart I've been to in Mississauga, Brampton, Milton, Oakville, etc, all have plenty of GC. So I find it odd that you couldn't find it when you lived out here.

I wouldn't run GC in that engine anyhow, stick with a good 5w20. Right now you can get a 4.4L jug of Canadian Tire's 5w20 (which is made by Shell) for just over $10. Or Quaker State 5w20 for $3.19 on sale this week at CT. No need for synthetic oil in Vancouver, your climate doesn't get cold enough and you can safely go 8 to 10,000 km on conventional oil nowadays anyhow.

But if you absolutely must go with synthetic, then you could go with CT's synthetic, which often goes on sale for under $20 per 4.4L jug. Or Amsoil 5w20. Just be sure to run these oils longer than 10,000 km if you want to get your money's worth. Otherwise you might as well just stick with conventional oil.

Oh ya, one more thing, welcome!

 

[Johnny]

Quote:

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Lets go back to Viscosity 101.

Motor oil viscosity is very temperature dependant.

A 5W-20, 5W-30 & 10W-30 are all in the 100 cSt to 150 cSt range at room temperature.

When the engine starts-up on a 72 degree day & goes thru the 3-10 minute warm-up stage, the motor oil slowly drops in viscosity from the 100+ cSt range to the final full operating temp of 100C,(212F), which is about 10 cSt for a 30 weight & 8.5 cSt for a 20 weight.

Only at the 100C temp range, is the oil a "20 weight", a "30 weight" etc.

So, the typical engine is required to operate on a broad range of oil viscosity thickness.

Now, an engine operating at high rpm, generally demands about 10 psi oil pressure per 1000 rpm, such as a high load, racing situation. This is were the 20 weight or 30 weight oil viscosity and bearing clearances becomes critical.

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Blue99: Well stated.

 

[Pablo]

I think Amsoil pricing is pretty good in CAN$ dollars:

5W-20 XLM $5.65 (Can. PC price) $7.45 (Can retail)
0W-20 ASM about $7 (Can. PC price) and about $9 (Can retail)

 

[Triple_Se7en]

Just buy a name brand that's on sale. If your engine likes it, then stock-up the next time there's a sale.

 

[unDummy]

6i or 6s?
There is no need to up a weight. Both engines available in the 6 are rugged and reliable. Go too thick and you might think its sluggish and possibly hurt MPG.

Any full synthetic name brand will work well. With those stores mentioned, there has to be several 0w20 or 5w20 full synths to choose from. I'd stick with the 20wt simply because you are up north and your yearly average oil temp is cooler then southerners like those from Florida or Texas, where I'll push the 30wt.

GC is a great oil. But, this doesn't mean that everyone needs that thicker oil. Same goes for the 0w40 and 5w40 oils. I'll go thicker when vehicle has higher mileage, oil consumption or leak issues, and known engineering deficiencies(like oil PSI or oil temp).

Since oil is rarely at room temp, and if you do perform several oil changes a year, stick with the 20wt's for the fall/winter usage. And, if you feel the need for thicker oils, then use the 30wt only during spring/summer oil changes. This way you can save money during the summer!

 

[Rodbuckler]

Quote:

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So, the typical engine is required to operate on a broad range of oil viscosity thickness.

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Yes but only for the specified type of oil, like 5W-20.

 

[BullyT]

I live in Newmarket, north of Toronto and I was at Canadian Tire this morning and they plenty of German Castrol 0W30. Our local WalMart also carries it, and so does Parts Source. I believe Parts Source has about 60 locations across Canada so maybe you can find GC at your local Parts Source, it not Canadian Tire or WalMart. I'm running GC in my BMW 740iL and it's great stuff--excellent for cold-weather starting, no oil consumption to date, and I know it's a true synthetic. BMW V8 engines run hot - they also hold 8 liters of oil - so I want to be sure I'm running the best oil I can find.

 

[jaj]

Mazda6Lvr

I sympathize with your problem - but I've had more time to do research. Here goes: GC 0w-30 is available at the North Van Walmart and at the New West one (south end of Queensborough Bridge - more like in Richmond). It's also at the 8th and Cambie Canadian Tire.

If you go to Lordco Auto parts (any lower mainland store, and there are lots, open seven days a week) they have Pennz Platinum in stock as well. I think Walmart has some selected grades of PP as well.

Good luck
JJ

 

[Blue99]

Look, what we are talking about is simply the physical properties of a motor oil.

A SAE viscosity grade is measured at 100C(212F) degrees. As an oil cools down from 212F degrees, the oil gets thicker.

Here is a comparison of a 5W-20 vs a 5W-30 motor oil at various temperatures up to the final 100C(212F) temp that determines the SAE grade:

Code:

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Viscosity in cSt

TEMP Pennzoil Pennzoil

C F 5W-20 5W-30

0 32 431 551

5 41 303 391

10 50 220 284

15 59 162 211

20 68 123 159

25 77 95 123

30 86 74 97

40 104 47 62

50 122 32 42

100 212 8.2 10.5

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Note that if you started up your engine in Virginia this past winter, and the temp was 32F, the 5W-20 oil in your crankcase was 431 cSt and did not reach the final 100C degree viscosity of 8.5 cSt for a 5W-20 until the engine had been run for 5-10 minutes.

An engine can be spec'd for 5W-20, but that does not mean anthing thicker will not work as even a 5W-20 is 50 times thicker when cold vs. hot.