C4 engine oil

[ness5353]

my new corvette mechanic said to use Royal Purple 10w40 synthetic engine oil in my 93. is this good stuff??

 

[Ken]

Let me put it this way, I haven't heard any bad reports regarding Royal Purple motor oils. I don't know if I'd believe the added horsepower claims they claim it releases though. Take that with a grain of salt.

In this case I think it's a matter of personal preference, or brand loyalty.

Seeing as how you reside in sunny Minnesota, I'd guess the oil's weight (10W-40) would be about right. As cold as it gets there, you might even want to consider 5W-40 or something similar.

 

[Daryllawman]

Welcome to the Corvette Action Center......Enjoy

 

[Hib Halverson]

Use a 10W30 synthetic oil in your 93. Unless you are racing the car and are experiencing very high oil temperature, there is not reason to use a 40 wt.

As for Royal Purple, my experience researching Royal Purple vs. Red Line Oil was that the Royal Purple organization could not supply any credible data that said it was better. As Red Line has been in the premium synthetic oil business for a lot longer than has R.P., I stick with them.

Either Red Line, or if the cost is too high, Mobil 1 10W30 are the ways to go, IMO.

 

[caddy]

I've used Royal purple and I've used Mobil 1, I have only used Mobil 1 in my corvette, however from what I understand Royal purple is a very good oil if you'll go here on the internet you can find out what you need.
http://shop.store.yahoo.com/racingsuperstore/roypurlub.html

Here's another myth about using syntheic oil in older cars:

Mobil 1 with SuperSyn™ does not cause leaks. It is fully compatible with the elastomeric materials from which automotive seals and gaskets are made. ExxonMobil engineers are wary of conventional oils that tout their use of additional seal-swelling agents. With extended use, these agents can over-soften engine seals, resulting in leaks. More to the point, an oil additive will not rejuvenate worn or damaged seals. The damaged seal may have been caused by a worn rotating metal component in the engine. If an older engine is in good condition and does not have oil leaks, Mobil 1 with SuperSyn™ provides the same advantages as when used in a new engine. ExxonMobil recommends taking measures to repair the leaks, then using Mobil 1 with SuperSyn™. ExxonMobil also always recommends following the automobile manufacturer's manual for the proper oil to use.

and here is another interesting fact:

Mobil 1® comes as standard equipment in some of the finest production vehicles you can buy. It's "factory fill" in Chevrolet Corvette, all Porsches, Mercedes-Benz AMG models, Dodge Viper, Ford Mustang Cobra R and all Aston Martin cars.

Just my 2 cents

 

[Galen]

I have used Mobil 1, Redline and Klotz synthetic oils. I have used them racing and my favorite is the Klotz we have used it racing for 10 years and have not had 1 oil related engine failure. We use Red Line exclusively in our driveline with no falures. I have friends that use Mobil 1 that are happy with it. GM Performace recomends Mobil 1 But they are allowing us to use Klotz in our test motor as well. The Klotz oil has a very unique smell almost a sweet smell like candy. When we change bearings in our race motors they still look new. I have also been using Klotz in my Chev. Pickup with a turbo diesel for 80,000 miles which has a rough life only pulling the race trailer. Remember synthetic oils are not the same viscosity as regular oils. They are actually thinner with the same rating. I use 20-50W year round in the Diesel and never have a problem. I live in Mich so it gets cold. I buy it in 55 gal drums so I only use the 20-50 in everything. With 20-50 in my L98 the oil pressure is the same as with 10-30 Valvoline full synthetic. Yes I was lazy and did the quick change at valvoline once. That is another story ended up draining 3 qts out of the poor thing to get the level right after a 600 mile trip that I could not figure out where the vibration in the motor came from. Can you say oops.

Galen

 

[Tuna]

Listen to Hib!

 

[Edmond]

my new corvette mechanic said to use Royal Purple 10w40 synthetic engine oil in my 93. is this good stuff??

I think it was Horsepower TV that did some test on Royal Purple. They had a Camaro SS and dynoed the car. They then changed the engine oil and tranny fluid to Royal Purple. It picked up something like 7-8 horsepower. I don't know if that was just paid advertising or the truth with Royal Purple.

I use Mobil 1 synthetic 10W-30 myself, just changed the oil today and I'm on my second K&N oil filter. That hex nut makes changing the oil so easy!

 

[Alex D]

Royal Purple has not had the best results in terms of wear. It is also a very thin oil in each of its viscosity groups and our LT and LS engines seem to fare better with viscosities of 12 cst @ 100C (Amsoil 10W-30, 5W-30, German Castrol 0W-30) than 10 cst @ 100C (most 5W-30 and 10W-30 oils such as Redline, M1, etc.)

Funny enough Redline is made from the most shear stable and heat resistant base stocks, di-esters and has a very stout additive package with more Moly (600 ppm) than you can shake a stick at (M1 and most other oils with Moly have only about 50 ppm), but in the UOAs (Used Oil Analysis) it does not seem to fare so good.

Best oils we have seen so far in terms of UOAs are Amsoil ASL (5W-30) and ATM (10W-30) and the German made Castrol Syntec 0W-30 (red label, actual this is Castrol SLX and a true synthetic, not hydrocracked dino juice) that Castrol is phasing in now in the US replacing the US made hydrocracked 0W-30 Syntec (Yellow label).

Look for all you want to know and then some on www.bobistheoilguy.com forum

 

[froggy47]

Hib,

What weight would you use in San Diego, LT4 engine, 50k miles, pretty mild year round here? A few 85-90 degree days in summer, maybe a Vegas run or 2.

Thanks!

 

[Hib Halverson]

What weight would you use in San Diego, LT4 engine, 50k miles, pretty mild year round here? A few 85-90 degree days in summer, maybe a Vegas run or 2.

Same as what I use up in West Covina in my LT5...Red Line 10W30.

When you make those "Vegas runs" which route do you take?

In difference to Alex D's post about UOA, for about a decade I've been using Red Line oils in a variety of engines. All with extended drain intervals. At every oil change, I have a sample spectrographically analyzed (UOA). The lab I use is "The Analysts Inc." and I have used them since the early 1980s when I was in the heavy-duty trucking business.

The only time I have seen a Red Line UOA I'd even consider marginal, was during some very long drain intervals I tried for test purposes back in the late 90s. A couple of times, I took Red Line to 22,000 miles between changes. UOA of a sample of that showed viscosity had jumped a full SAE grade, but the anticorrosive additive package was still servicable. Wear metals were about the same as they were for the entire 140,000 miles I ran this engine. The test subject was a 2.8L GM V6 run in a duty-cycle that varied from normal to severe duty. The engine received filter changes every 3000-4000 miles and had oil consumption of 3000-4000 miles per qt.

After this test, I settled on 18,000 miles as an oil drain interval on engines, using Red Line Oil, in vehicles that were driven more than 10,000 annually.

While Amsoil and some of the true synthetic Castron Syntec products might perform better in a simple comparision of UOA statistics, in a practical sense, I wonder how much better those two products really are?

 

[lt1george]

Why use 10w 30w, when recommended by Chevrolet is 5w30w ?And what's wrong with syn. Mobil ?

 

[Alex D]

Hib,
Your point is well taken. My comment was not to knock Redline. I am using redline in our 2001 Trans Am and in our 2002 Suburban right now. My 1996 Vette runs on Amsoil and I can't get the German Castrol here yet.
Redline is an excellent oil, no doubt.
My point was that the UOAs I have seen on Redline have consistently higher wear numbers than those with German Castrol and those with Amsoil. This may be caused by the excellent detergent and cleaning abilities of di-esters or other reasons.

 

[Edmond]

Hib,

What weight would you use in San Diego, LT4 engine, 50k miles, pretty mild year round here? A few 85-90 degree days in summer, maybe a Vegas run or 2.

Thanks!

froggy,

Driving everyday in San Diego would be considered normal driving right? But due to the Vegas climate and all, would Vegas driving be considered a little more extreme and therefore call for shorter intervals between changes?

 

[XS650]

But due to the Vegas climate and all, would Vegas driving be considered a little more extreme and therefore call for shorter intervals between changes?

Edmund, all that really matters in that case is oil temperature. Oil temperature is effected by a few things, mainly how hard you run the engine, coolant temperature and ambient air temperature.

The main variables going from somewhere reasonable to Las Vegas are coolant temperature (if you cooling system isn't adequate) and ambient air temperature. Figure that oil temperatures will be less than 20 degrees hotter in 20 degree hotter air, maybe much less hotter.

There are some people in the hot parts of the Southwest on the list, maybe they will volunteer their oil temperature differences between something like 90 and 110 degree weather.

 

[froggy47]

Hi Edmond,

Actually the daily San Diego driving I do is probably more "extreme" than a trip to Vegas. I usually take the Vette out at night (cooler engine start temp) & drive a short distance to my gym. Oil temp gets to about 145 F. After a 1 to 1.5 hour workout I hop back in (still pretty warm) and bring it up the rest of the way 185 - 190F (talking oil temp).

Then I have some fun & get thru 1,2,3 (maybe 3rd gear if traffic & safety permit) gears a wot/6,000 rpm. Ahhhh, what a feeling.

Full round trip is maybe 10 miles max. My little speed fix for the day.



In any event, because of the short cycle every day & autox 1 or 2 a month, I run synthetic (Mobil 1) a good filter acdelco/mobil1/k&n/napa. And chg every 3500 -5000 miles & top off as needed.

Hib,

I've been thinking about Redline, but, I'm on extended warranty and there's always that chance that the dealer or Warr company will try to weasel out of a repair - non GM blah, blah - so I've stuck with the GM "approved" lube for engine, tranny, dif.

LT1George,

If you read the owners manual you'll see that 10w-30 is approved (some say preferred) if the ambient temps don't drop below a certain degree, let's say 30deg F) The 5w-30 is for easier starting & quicker lube w/ cold engine&oil if you live where it gets cold. New England, N. Dakota, fill in your favorite cold state.

If you live in S. Calif or Florida or S. Texas how many times will you start the car at a below 30 deg F temp. In my case never. So 10w - 30 is preferred over 5w- 30 for where I live. GM makes it's basic 50 state recommendation just to cover it all with one weight oil.

To make an oil 5w-30 instead of 10w-30 the manufacturer has to add some "stuff" that's really not optimum for lube/cool/anti corrode the parts of the engine. It's OK but not optimum.

I believe the fewer numbers 10w-30 rather than more 10w-50 for example is better.

Jump in guys if I've got something wrong here.

Thanks for the posts!

 

[XS650]

I've been thinking about Redline, but, I'm on extended warranty and there's always that chance that the dealer or Warr company will try to weasel out of a repair - non GM blah, blah - so I've stuck with the GM "approved" lube for engine, tranny, dif.

They can't make you use GM oil unless they supply it for free. But theycan require you to use oil certified to a certain spec if there are multiple sources for that oil. More than one oil meets their spec, so you have to use it if you want to be sure your warranty is will be honored.

I searched for Redline at
http://eolcs.api.org/
and couldn't find them, so they apparantly aren't even certified to meet the near universal API specs that Walmart and Safeway oil meets. Chevy require that your Corvette engine oil meet API specs and have the API starburst seal on the can. Potential bad news if it doesn't

Chevy, at least for my '96, also requires oil that meets spec GM 4718M. If Redline doesn't certify in writing that they have tested their oil to meet that spec, then your warranty wouldn't necessarily cover a lubrication related failure.

In general, if the oil you use isn't certified to meet the specs that the manufatuerer calls out, you are skating on thin ice.

I have no doubt thet Redline is one of the best oils made, but if you have an oil related falure while running a non-approved oil, you are depending on Chevy's good will, and not your warranty contract.

Dick

 

[Alex D]

API certification is meaningless in terms of oil quality. It has more to do with fule conservation and addititve levels (environmental). If you want to judge an oil by its rating and are interested in performance, look at the European ACEA ratings. The best and most resilient motor oils on the market today carry an ACEA A3/B3 rating. ACEA A1, A5, B1, B5 are lower quality ratings. Also looking for Daimler Chrysler rating of 229.3 and 229.5 will tell you that this is a high quality oil. These EU ratings tell you about shear stability, viscosity retention, adequacy for extended oil drain intervals (Europe has average oil drian intervals of 10,000 to 15,000 miles, while they are only 5,000 to 10,000 miles in the US)

Among other items, API certification requires that the oil meets their standards in terms of additive volume and fuel conservation (starburst symbol).

With forward going API certifications (SF>SG>SH>SL), additive packages such as ZDDP (zinc) were actually reduced significantly.

Many high quality oils such as Redline, Amsoil etc. do not meet these because their additive packages are too stout for APIs latest certifications. A heavy additive package though is important for a high performance oil and especially when you think about extended drain intervals.

Having an API certified oil means nothing to me and has no impact on oil quality whatsoever. Amsoil actually sells their XL-7500 series oils which are API certified just to have an API certified oil available. This stuff is their cheapest oil, a hydrocracked reformulated dino oil (a la Castrol Syntec) and carries the shortest drain interval recommendations from Amsoil....but its API certified. Their better oils are not.

 

[XS650]

Having an API certified oil means nothing to me and has no impact on oil quality whatsoever. [/B]

That's all well and good, but by the original concern was about warranty compliance. If a person doesn't use oil that meets the manufaturers required specs, the part of the warranty that covers lubrication related failues is null and void.

The chance of a lubrication related failure during warranty is relatively small, and a good ethical manufatuerer or warranty provider would try to honestly evaluate whether the failure was actualy caused by the oil or not. But, at that point you are depending on their good will rather than contractual requirements.

Before someone uses non-spec oil while on warranty, they should be aware of that and make a conscious decision to take the risk if they choose to. The "experts" singing the praises of non-compliant oils usally don't bother to mention that little potential gotcha.

Dick

 

[Alex D]

hey, everyone can do what they want ...... I am not advertising here for Redline or Amsoil ...... besides, the manufacturer cannot (!) void your warranty if you use a non-API certified motor oil.

That's all well and good, but by the original concern was about warranty compliance. If a person doesn't use oil that meets the manufaturers required specs, the part of the warranty that covers lubrication related failues is null and void.

The chance of a lubrication related failure during warranty is relatively small, and a good ethical manufatuerer or warranty provider would try to honestly evaluate whether the failure was actualy caused by the oil or not. But, at that point you are depending on their good will rather than contractual requirements.

Before someone uses non-spec oil while on warranty, they should be aware of that and make a conscious decision to take the risk if they choose to. The "experts" singing the praises of non-compliant oils usally don't bother to mention that little potential gotcha.

Dick