Kman

I have been running the German Castrol 0w-30 in my car, but they don't sell it at Auto Zone anymore. Is the Mobil1 0w-40 the next best thing?

Awhile ago I tried Mobil1 5w-30 and the car burned oil. When I switched to the GC 0w-30, the oil burning stopped.

I guess my question is, now that GC 0w-30 is no longer sold at Auto Zone, what is everyone running?

ChocoTaco369

Yes they do. It's just at the larger Autozone's. The one near me just got a whole new shipment. I bought 12 quarts on sale for $4.49/quart. They're on sale until August 22nd. They also changed the look of their bottle.

You should be able to order a few cases at the counter. Just because it isn't on the shelf doesn't mean you can't get it.

Plain and simple, nothing Mobil 1 is the next best anything. Mobil 1 isn't what it used to be. 5W-40 is a better oil than 0W-40, and if you absolutely have to go Mobil 1, I'd go 5W-40. I ran some and my car burnt quite a bit of it and it and the engine was quite a bit louder with it than with GC 0W-30. I got the LOW OIL light with Mobil 1 5W-40 after a measly 4,000 miles. I've never gotten a LOW OIL light running GC 0W-30 for 5,000 miles.


Again, it is. Just order some.

Kman

Ok. I thought I saw a thread that said it was stopped being sold. Now that I know it is still sold, I'll go stock up again.

Is the bottle still black with red lettering?

ChocoTaco369

Yea. I'll take a snapshot of the new bottle for you sometime today or tomorrow if I get around to it. It's getting dark here and I don't feel like sorting through the garage

The smaller Autozones aren't carrying them. I haven't seen them restock the small one around my house for a while, but the larger one i just bought 18 quarts from 2 months ago while they were on sale and they restocked with GC in a new bottle and I got 12 more also on sale.

Just ask at the register. I'm sure they could still order it even if they don't carry it for store stock anymore.

LS1_Disciple

iTrader: (1)

The Autozones around me stopped carrying it, but the O'Reilly's does. They keep cases of it in the back, but don't put any out on the shelves (?). They can also order more if they happen to be out of it. Check with an O'Reilly's if you've got one near you - they seem to be good about ordering stuff.

FastB

iTrader: (11)

You can probably find it on the internet and order it if you are having trouble finding it in the stores. I used to have an Audi and sometimes I would have to call several stores before I found it.

Braunbeck

iTrader: (4)

I used Mobil 1 10-30 and it burnt up quite a bit between changes. I've always used 0-40 in my turbo applictions in the past so this oil change I decided to go back to 0-40 and it has been nothing but great so far. No burning at all and holding up just fine in the Arizona summer.

I've tried to find the GC, but no-one carries it around me.

Mr Incredible

M1 is known to have problems with evaporation (seen as usage) and produces higher iron numbers than most oils. M1s best asset is the marketing department.

Kman, you can look through the chart below and find any number of oils that will work as well or better than M1-anything at a better price.

Braunbeck

iTrader: (4)

what the hell does that chart mean? is to top the best or the bottom?

need some more info to hel understand

Mr Incredible

The chart shows the relative viscosities of different brands and weights of commercially produced passenger car motor oil.

The best oil is the one you choose because you understand what you are choosing and why.

If you are looking for an oil of similar viscosity to GC, read the chart and go buy what you think is right for your application.

bayer-z28

iTrader: (14)

My buddy uses 0w-40 in his LT1.. we'll he used to till he sold it. We have a hard time finding GC here.. Small town, small stores.

I've allways ran either Syntech 10w-30 or Mobil1 10w-30 in my LS1. NEVER used regular oil.

Mr Incredible

The absolute, most often cited reason for the use of either GrIII or GRIV synthetic is "because I want to use the best for my car." This is admirable, but not necessary.

For oil change intervals of 3k to 4k miles you can hardly justify the cost of true synthetic oils. Modern oils have come a long way and have increased in quality dramatically.

The only justifiable use of true synthetics is for extreme cold, extreme use (true racing, not just driving crazy), or extended oil change intervals (above 6k miles).

That's my opinion, you're welcome to your own.

Kman

Can you explain the different numbers and what they mean? I don't see GC 0w-30 on that list?

Mr Incredible

GC is listed as Castrol Syntec 0w-30 (GC).

The numbers are the viscosities at different temps. cSt is centistokes, a measure of viscosity.

cSt at 40*c is the viscosity of the oil at 40* celcius. This is equal to 104*F. 100*c is equal to 212*F. HTHS is the High Temperature/High Shear Test (HTHS). It measures a lubricant's viscosity under severe operating conditions. Higher numbers are better.

I have used the thinnest oils on the 5w-30 chart (Havoline Deposit Shield and Castrol Syntec) and come up with about the same numbers in a used oil analysis (corrected for miles) as I did with M1 5w-40 Truck & SUV. The M1 TrSuv, however, had much higher iron amounts. All numbers were well within the good ranges, and the results were quite comparable. It is for that series of tests that I conclude the LS1 does not really care what viscosity of oil you use.

With that taken into account, the questions left would be why would I care what viscosity of oil or particular brand of oil I use? For that matter, why would I care whether I use a real synthetic or a fake synthetic oil?

I won't go into detail about the synthetic question, as there are about ten billion pages on the subject. If you don't know, go find out. The Reader's Digest version is that true synthetic oils are more stable at high temps, produce less sludge particles, and will last longer for those who wish to extend their oil change intervals.

As for which viscosity, that's a personal choice. I have found that thinner oils make no more noise than thicker oils. In fact, I have less piston slap with the thinner oils.

Thicker oil made my car seem sluggish, like it was carrying around a heavy backpack. The piston slap was pronounced on cold/cool mornings.

GC is popular, I think, because one or two particular people had very good luck with it in their LS1s. GC is a true synthetic oil. GC is expensive and hard to find for most people. It is an outstanding oil, but it is NOT the end-all and be-all of good oil.

I have GC in my car right now. I purchased it before I did the thin oil test. The car feels strong, runs well, doesn't feel as sluggish at M1 TrSuv did, and will stay in for 5k miles before I change it. But, once I use up my stash I doubt if I'll buy any more unless it's on sale and I can find it all at the same time.

All this leaves is what particular brand of oil you would want, and what viscosity you would want. Different brands/weights have different additive packages. Some are robust and will last a long time. Others are weaker and suitable for regular oil change intervals. You might choose a little lighter visc oil in the winter and maybe a little heavier visc in the summer. Maybe. I doubt if it really matters that much to the LS1 as much as it does to people who agonize over every little thing with their wonderful, beautiful, powerful Camaros. The LS1 can overpower thick oil and doesn't have any problems with anything in the lower viscosity 30w's.

Again, this is my opinion base on years of interest in this subject. The big difference, however, is that you search out answers to your questions and don't simply take somebody else's word for it. Sometimes you have to (like brain surgery), but not on something as simple as oil.

Seek, and ye shall find.

johnnybravo

I would have to agree. I've used Havoline for the last 20+ years in all my autos. Never had a problem. It's also reasonably priced and readily available. Two of my favorite features.

When I got an LS1, guess what? At its next scheduled oil change, in went Havoline. I always use the weight specified by the owner's manual. I also keep 6 to 12 months supply on hand so I have the option of picking some up while it's on sale. Rarely do I pay regular price.

xny1989

iTrader: (1)

When I first bought my 99 z28, used, with ~ 67,000 miles, I started using M1 5w-30. The oil would get dark and dirty within a thousand miles, and I would loose a quart. After several oil changes over the last years, the oil stays cleaner, longer, and I don't loose any (or very little) between my 3,000 mile interval changes. I suspect the previous owners didn't maintain the car very well, leading to the dirty oil and oil loss, with the situation improving as I better maintained the car.

Given the information Mr. Incredible has provided, and wanting to control costs, and given the fact that the car is a daily driver, will not go to the track, an occasional street race, and the fact that I change the oil religiously at 3,000 miles, what would the value of a semi-synthetic vs. full synthetic. I use the semi's in my family's other cars (Honda's), and regular oil in my 'toys' (72 GMC sprint and 65 olds cutlass).

Braunbeck

iTrader: (4)

Mr. Incredible, do you own an oil forum or a page that dicusses oil? Back in '00 I was involved in a conversation and was directed to a page dedicated to oil topics and research. Was very cool, at that time I have a turbo'd 4 cylinder hybrid motor (different head/as to bottomend-Honda setup). The motor was fully done and had one of the first AEM PnP's on it. I wanted to run a great oil that wouldn't bust my budget. The topic came up about using the Pennzoil Deisel/Heavy Duty 15-50, it had extra corrosive protection since it was designed for deisel engines as well as other key features. I miss that site and haven't been able to find it, this person used to post on Club Si, was curious if you had a page or could point me to one.

Thanks

Sharpe

iTrader: (7)

OH!!! How ******* DARE you speak against the GC Cult of Divine Lubiosity!!! You are going to ******* hell you baby seal-killing bastard!!!

You can take your godamn "facts" and "charts" and "logic" and get the hell out! GC is so great it lubes your engine and sucks your **** at the same time! Put that on a chart, bitch!

1QUIKWS6

iTrader: (61)

Wow

I use the GC 0w-30 for reasons cited above - my car is a show car, not a whole lot of mileage per year, and it sits in the garage all winter. I change the oil/filter beginning of every season just to be sure that a lot of condensation hasn't built up in the oil over storage & because my car doesn't get a chance to regularly run at higher temps to get rid of water in the oil.

Viscocity and HTHS is more than decent. Used to run M1 - after using GC my HS rockers/drivetrain quieted down noticeably - never really had a problem burning oil with any brand used, and my catch can only picks up a minute amount over the year. Oil pressure with both and LS6 ported/coated/shimmed oil pump is about the same.

1QUIKWS6

iTrader: (61)

Actually just got back from my nearby AZ - picked up another 12 qts. of GC 0w-30.

Price on shelf said $6.09/qt. when it rang up, it totalled $73.08, then gave me a 'Total Deal Discount' of $19.20 bringing new total to $53.88 - that's $4.49/qt. - not a bad deal at all

Here's pics of GC Oil - red/black bottles (make sure you look on back of bottles - should say 'Made in Germany' directly to right of 0W-30 designation on back bottom label as in 2nd pic