0W40?
 

Starting in 2019, GM changed to a 0W40 engine oil for all Corvette engines except the LT6 which uses a 5W50.

Has anyone tried a 0W40 in the first generation LT5?

I would think that the same two major advantages?1) oil gets to bearings more quickly on cold starts and 2) better thermal stability during aggressive engine operation?that GM gained with using a 0W40 in the 2G LT5 and the LT2 woulid be useful in the original LT5.

Re: 0W40?
 

I put it in my '90 (Mobil 1 0W40 European formula) because of the higher zinc and phosphorous and it seems to work well, quick starts, no noises, temps and pressures normal, no problems, can't see any difference in performance from the original Mobil1 that was in there before. Only time will tell.

Re: 0W40?
 

No experience with the Euro 0W-40, but I just changed my oil to Mobil Formula M 5W-40. No issues and quiet start up. Karl can tell us more about Formula M, but I like it so far.


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Re: 0W40?
 

I am using Mobil 1 Formula M 5w40 with no issues.

The European motor oils appear to have more zinc and phosphorus.

Car runs great and this is used in my 401 cid LT5. I chose this weight combo for all the reasons mentioned above.


https://i.postimg.cc/Fdt8Bb0x/Screen...909-060521.jpg

0W40?
 

Karl,

Thanks again for the recommendation. I have not drank the AMSOIL Kool-Aid and they will not reasonably ship to military address overseas; Mobil 1 Formula M is easy to get. BTW, your image you posted is blurry AF.


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Re: 0W40?
 

Edit

Re: 0W40?
 

Thanks for the replies, folks.

For those who use M1, the latest 0W40 is "Mobil One Supercar". Among others, it's the factory fill on C8s w. LT2s. M1 "Supercar" is the 10W40 ESP that was rebranded.

Re: 0W40?
 

Every time this question comes up, some are quick to say they have tried it in their motors w/o any issues. But, lubrication issues seldom pop up until considerable run time has occurred under typical wear scenarios or under stressful scenarios.

I dunno 'bout Uz, but I can't afford to experiment with my engine - too rich for my not-so-deep pockets. Therefore, I would prefer to see some comprehensive, scientific testing and comparisons between historic results with a former recommendation lubricants and the new product (good as it may be!).

Our LT5s are flat tappet motors and rev limits are ~ 7100 rpm to 7500 rpm (in some modifications). And, the ZDDP of the oils recommended at the time they were being built (by Mercury Marine), the zinc/phosphorous levels were in the ~1200/1300 ppm - to accommodate the demands of those (LT5) engines.

However, air pollution mandates resulted in reducing (in part) the ZDDP levels. And, offsetting the reduction of reducing the ZDDP, flat tappets gave way to roller tappets and rocker arms, etc.; both roller tappets and rockers are still in use today. My point is: aren't we comparing apples to oranges here? That isn't to say that this or that GM oil recommendation will spell trouble for our first gen LT5s. But, it remains to be seen if the new oil recommendation can bridge the gap between the specific application (roller tappets/lower rpm vs. flat tappets/high rpm) requirements.

Your mileage may vary. But, as for me - I'll stay with the "Kool-aid" until something else proves to be better...hopefully in an application other than MY LT5! Just sayin':)

Re: 0W40?
 

Excellent Summary Paul :thumbsup::cheers::cheers:

Re: 0W40?
 

Well said!

Re: 0W40?
 

It is extremely difficult, nearly impossible, to prove something cannot possibly happen.
However, that does not mean that it can or will.

The Zinc and ZDDP content of the 0-40 is higher than most of what is often currently being used in these and other older engines.

Religion, politics and yes, oil, are very often controversial subjects.

Mobil One has been around since 1976.

While I understand it's formula has had to undergo changes, for mostly political reasons, i.e. Reduced exhaust emission requirements for catalyst longevity, that does not mean that it destroys engines.

I continue to favor Brad Penn for my LT-5, but I would not hesitate using Mobil One 0-40, and may even switch to it on my next change.

You may call me a Heathen, but I do have faith in companies such as Mobil and their products.

I do not believe or expect that this will change anyone's opinion, and that is OK.

Use whatever, as you wish.

Be happy!
:cheers:
Marty

Re: 0W40?
 

Beaky Buzzard once said....you can't fool me because, I'm a moron. With that said, I'll rely on others. My 90 is scheduled to go to Haibeck and whatever he recommends is good enough for me.

Re: 0W40?
 

Playing the devil's advocate...

LT5s with stock valve train don't need that level of zinc and phosphorous (which was formulated with pushrod valve gear in mind) because the cams act directly on the tappets. There are no pushrods and no rocker arms. That means less mass and since there is less mass, even the stock 1G LT5 valve springs have significantly less tension than valve springs in pushrod engines, thus the pressure over the nose is less and...there is less need for the extreme pressure additive ZDDP.

I no longer have Mobil 1 data sheets going back to the 90s so I can't quote facts, but I'm not convinced that all the factory fill oil used back then has 1200-1300 PPM phos.

Re: 0W40?
 

Hib, there comes that "Beacon".

Graham

Re: 0W40?
 

Apart from the ZDDP discussion wouldn't it be interesting to to know about the positive effect of high viscosity oil during cold start? That's where engines are supposed to have the highest wear. At least according to what I read about it.

My personal experiences are:
- with those super thin oils the chance of leaking dramatically increases the thinner they get.
- the best way to get great engine performance and lifespan is to treat it well. Proper brake in (which unfortunately the least uf us can control in their 30 years old ZR-1), patient warm up & plenty cool down phase, high quality fuel and regular/frequent oil chances make engines purr like kitten. No oil can offset poor usage - but good habits can, to a certain degree, offset a poor oil.

My 1995 Audi S6 4.2 still consumes no oil, doesn't smoke at startup or during hard acceleration, runs smooth as silk and pulls like a freight train (though compared to the ZR-1 I have to say: like a steam train). I tried many different oils in this car over the last 22 years of ownership (with strict annual oil change). 0W30 was the thinnest. But I always treated the engine with love and care. I don't claim that this is the ultimate way to success but at least in my case (includes all my other cars) it worked well.

Back to my question above: how much would 0W instead of 5W or 10W support a well lubricated engine start and thereby reduce wear?

Re: 0W40?
 

I hear LT5 valve tension being less than that of typical push rod engine. However, shouldn't we also enter higher RPM into this equation?
I had used Mobil 1 products for years in my 94 ZR-1 (as well as long departed 91 ZR-1) until I found out that Mobil has quietly reduced the Zn and phosphate content and eventually turned to Amsoil.
For me with less than 5,000 miles being put on my 94, a bit of hassle and cost once a year in exchange for a peace of mind is well worth it.
Below link should take you to the latest Mobil 1 oil specifications.
https://www.mobil.com/lubricants/-/m...pecs-guide.pdf

Re: 0W40?
 

Rotella T6 5w40 is a good option if you're looking for a 40wt synthetic oil with a lot of zinc.

Re: 0W40?
 

The ONLY reason 0w oil was created was to reduce emissions and increase fuel economy, primarily during a vehicles warm up period. Anyone who says anything else is drinking the corporate kool-aid from the auto manufacturers. I spent years at a company that built air cooled aircraft engines that were used in environments with starting temps well below zero and places with starting temps well above 3 digits. We've done our research and operate in a market devoid of emissions regulations (for the time being). Zero weight oils were created in Japan for emissions and fuel economy. You know, the country where it was cheaper to buy a new car than to continue to run a car with 55k miles due to emissions and other restrictive requirements like the "shaken" law.

There is no measurable benefit to 0w oils on start up unless you are comparing them to straight 50 weight or gear oil. Sorry. The car manufacturers and the government are trying to dupe you.

Run what the manufacturer recommended originally or slightly heavier depending on driving conditions and style. That recommendation came from before the environmentalists became so woke and figured out how much money was in it. While additive packages have improved, there is no magic to oil manufacturing from the 90's until now. It is almost exclusively driven by CAFE and emissions laws.

My 2011 Subaru Forester came with 0w 20 oil from the factory and the timing chain clattered like none other at startup until I switched to a heavier oil.

Re: 0W40?
 

I think Haibeck is still going with Amsoil 10W-40 on his web site 👍
"Amsoil offers their AMO product. I believe that it provides the best protection. It has the full EP additive package. In addition it is 10W-40 viscosity. The higher viscosity offers more film thickness, which adds to EP protection."

Let us know if that has changed 👍

I just got a case of Amsoil 10W-40 delivered today 😁😁

Re: 0W40?
 

Very interesting post. Thanks!

Re: 0W40?
 

NOT necessarily taking exception to what you stated re lighter mechanicals, i.e., pushrods and rockers, and spring tensions, etc. But, but, but! In the interest of physics, does not the forces to overcome inertia increase @ the square of the rate of acceleration (of the parts involved), AND therefore the task of the lubricity in the oil?

Again, the issue is direct vs. indirect "testing". Direct testing on the 1G LT5 is cost prohibitive, especially considering the lack of new or substitute parts. And, it takes significant runtime/stress testing to gather evidence enough to make any scientific, definitive conclusion(s). So, in absents of direct testing, we're relegated/obliged to accept INDIRECT test data results gathered with other (engines) operating with identical or at least practically close conditions.

My point is, the data for making a direct comparison(s) and much less predictions between results of this latest (Mobil 1) oil and that of products having considerably more real runtime data on actual 1G LT5s rests solely on a manufacture's reputation and little if anything else - comparatively speaking.

EXAMPLE: Various antifreeze makers provided a revolutionary coolant (referred to commonly as DEXCOOL; a coolant improvement over the traditional (GREEN) silicon base coolant which "Dex" superseded. But, if one were to replace their GREEN stuff with DEXCOOL solely on the assumption that the "DEX" was made by a reputable company and therefore suitable for their LT5, they were in for a very expensive mistake. Companies like Mobil 1 make a variety of products for various applications. But, applications differ, and one size does not always fit all!

Your mileage may vary....

Re: 0W40?
 

What is the maximum cam pressure on the lifter for an LT5 engine?

Going from a 4,000 rpm to over a 7,000 rpm engine is a BIG factor in Cam Pressure and wear.

I also know from an experience that the cam tips are not parallel with the Lifter surface on the LT5 engine. (Cam Tip being the high "edge" of the Cam that gives the Lifter maximum compression).

An Aberration in Cam Wear

The localized pressure on the lifter must be very difficult to determine in that case....

The Cam Wear on the tips can be seen on the Cams pictured below.

https://cimg0.ibsrv.net/gimg/www.cor...c24529c641.jpghttps://cimg1.ibsrv.net/gimg/www.cor...743514fa8c.jpg

I assume the cam tip being tilted and off center on the Lifter surface keeps the lifter rotating. The lifter rotating under the cam acts like a rolling intersection (not purely frictional). [B]The surface of the Lifter is moving vertically and horizontaly as the Cam Tip slides/rolls across the Lifter. (It is hard to imagine this happening up to 60 times a second).

Redline (maximum safe operational engine speed) is a BIG factor on ZDDP issues.....

Redline for L98 is 5,500 rpm.
Redline for LT5 is 7,200 rpm.

Mobile-1 for racing engines (high rpm) shows much higher ZDDP :)

Post 294 - Camshaft Abnormal Wear

A little more detail on Oil/Zinc/Cam Wear from Hib Halverson........:cheers::cheers:

Oil/Zinc/Cam Wear Part 1

Oil/Zinc/Cam Wear Part 2

Re: 0W40?
 

https://www.mobil.com/lubricants/-/m...pecs-guide.pdf

Notice on every Mobile 1 oil with API certification the recommendation states "Vehicles that require XW‐
XX."

There is not one spot in their product guide that recommends using a viscosity not originally recommended by the manufacturer.

Notice the zinc and phosphorus content on the racing oils...

Again, this whole topic is grayed significantly by the regulations governing oil, fuel economy, emissions equipment, etc. Aviation oil still has or recommends as an additive, Tris(methylphenyl)phosphate (Tritricresyl phosphate). Long banned in automotive oils and with relatively high toxicity, but in a market that is widely unregulated. A market that suffered many of the same issues listed in Hib's articles, such as the ceasing of lifter production by Eaton who's secret sauce recipe for lifters supplied aviation for a long time.

Another good read for those who really want to get into the weeds: https://www.mdpi.com/2075-4442/1/4/132/htm

Re: 0W40?
 

Interesting stuff for the engineering types out there. The paper gives a sense of the complexities if tribology, and the difficulty in balancing advantages and disadvantages of various additives for oil manufacturers.


My takeaways: motor oils are not all created equal; stick with what is known to work unless there's good reason not to; the devil is in the details.


Appreciate the reads!


:cheers:

Re: 0W40?
 

Thanks for the pointers to these articles. I imagine this is about as detailed a history as you are going to find anywhere on the topic.



Early in the Part 1 article, it is stated that the LT-5 having flat tappets is "... only peripherally related to this wear issue, because it had overhead cams and direct acting, bucket-type flat tappets." It would seem to imply that the LT-5 operating conditions are less severe, but I may be reading to much into that statement.


I'd be interested to know what drove the choice of ZDDP content for the LT-5 and whether it's valve train design is a more or less (or neither) severe case in terms of valve train loading and wear compared to older flat tappet OHV engine designs.


Also, if anyone knows, whether the recommended oil for the LT-5 changed at all between the different model years?

Re: 0W40?
 

It's generally accepted to be less severe than high performance pushrod engines. It's probably equal to or more severe than low performance pushrod engines.

However, emissions equipment life drove the ZDDP content for all API approved engine oils. Zinc deposits can reduce catalytic converter life. Interestingly, I haven't found any great articles on how much zinc reduces the catalyst life by how much.

Re: 0W40?
 

Redline (maximum safe operational engine speed) is a BIG factor on ZDDP requirement issues.....

Redline for L98 is 5,500 rpm.
Redline for LT5 is 7,200 rpm.

Mobile-1 for racing engines (high rpm) shows much higher ZDDP :)