Recent threads (on oil) have noted the changes in oil formulations to reduce zinc (and possibly other potential cat-damaging substances).

I talked to Mobil tech line yesterday and got a couple of pieces of info.

Oils (syn & conv) that have the "energy-conserving" rating have lowered zinc. These are mostly the 5w-30 oils. 10w-40 and heavier are unaltered. For older motors, you can use these if you have a concern.

BTW: I talked to a supervisor after I exposed the front-line guy as unknowledgeable.

The super also said that synthetics WILL seep thru seals and burn easier than conventials. This contradicts a recent "myth" that synthetics don't do this more readily. HAH! That's because they have consisently smaller molecular chains. (In fact, he said they often compare 15w-50 synthetic to 5w-30 convential).

He also confirmed that lighter weight oil creates more HP. (Something that seemed intuitively backward for me. I always thought heavier oil would improve compression and, therefore, HP. Yeah, lighter oil offers less resistance to the motor, but I'm a dweeb, O.K?).

I sited another forum member's response from Valvoline which said 20w-50 racing synthetic was a good choice in vettes! (This led me to purchase Mobil 1 15w-50 -- though I haven't loaded in my motor yet). The supervisor said he wouldn't recommend 15w-50 even though I never drive below 40-degrees and had a concern for the hot temps of the vette in the summer -- especially with the closed grill. He encouraged my to try the 10w-40 high mileage synthetic -- as it has higher zinc, better flow than 10w-40 conventional (that I've used), and better seal conditioners.

If I try that and it seeps too much, then I might consider the 15w-50.....

I'll probably remember more later, but this is something to get the thread started.....

gp

FWIW: I currently use about 1 qt in 3K miles on 10w-40 convential. When I tried 5w-30 synthetic a few years back, I used 1 qt in about 2-3 weeks!

 

hmmm, interesting .
i have 99k miles on my '01 and don't use any oil between 5K mile oil changes with 5W30.
I'm confused by your statement that they compare 15W50 synthetic to 5W30 tradional oils... compare them for what purpose? viscosity?

 

Greggpenn,
Do you have the phone number for the mobil tech line?I have a 95 with LT1 engine.The manual and logo under the hood states to use Mobil 1, 5w-30 oil only.I would like to ask them what are the other choices as far as Viscosity and Zinc.I would not use synthetic oil unless specified by GM.Mobil 1,5W-30 has cause a slight leak which I am having repaired. The previous did not use synthetic oil and it was bone dry.I would like to use a thicker oil than 5W but the LT1 calls out for 5W - 30.
Thank You

 

Whoa - you're reading my mind. I just this morning started a thread on the tech forum asking about zinc and Mobil 1. Your answer is great. And, by the way, I just noticed my 94 LT1 with 40K miles went through 1.5 qts of Mobil 5W-30 in a couple months (about 2K miles)... and no drips on the garage floor.. my "Low Oil" light came on and I 'bout had a heart attack. So, it must be going through valve seals and maybe past the rings, right? Think I'll switch to 10W-30 or 40 next oil change.

Thanks!

 

I'd didn't quite make sense to me either. Viscosity is what they eluded to (e.g., ability to flow). They were saying that equivalent viscosities of convential vs. synthetics did not flow the same. 15w-50 flows the same as a 5w-30 convential. If so, why not rate it that way????

 

800-662-4525 option 1 (English), option 1 (tech questions).


Mobil Clean 5000 or Mobil 1 10w-40 will have enough zinc. (They should leak less than the 5w-30 and aren't really "too thick". They might lower gas mileage microscopically. If you don't have flat tappet rockers, they say you don't need the high zinc anyway...

The high mileage formulas (conv/syn) contain other additives that are good for sludge and/or seal conditioning. Don't be afraid to try those -- even if age is more of a factor than mileage.

Synthetic is better in a couple of ways. It flows better at startup and in cold weather. It also retains good lubricating properties longer change intervals than convention oils. For those living in warmer climates and/or who don't drive in cold weather, synthetic has limited benefit -- especially if you change your oil at least every 5K miles!

I'm curious to try a heavier weight synthetic since I never really gave that a chance. When 5w-30 synthetic proved too thin, I went to higher visc conventional. I didn't try 10w-40 Mobil 1. At that time, it cost 3-4 times more and I didn't see the point/benefit. Recently though, Mobil dropped their standard blue bottle conventional line. All I could find was "clean5000/7500". And, the price (of conventials) had gone up since my last case purchase! I was thinking the clean 5000/7500 line was a gimic to get more of my money! After looking around, I found 5qt jugs of Mobil 1 @ WallyWorld for $23. (This price covers most of their synthetic Mobil 1 formulas). With the clean5000 being almost $3 qt -- and not being available by the case (at a case discount), synthetic isn't that much higher any more. It's $15 vs. $23. I can live with that -- even for limited improvement.


gp

 

Thanks for your quick reply

 

I use Mobil1 10w-40(regular syn, not extended life) full syn in my LT5 and I find that at Costco. They sell it in six qt boxes for about $30,00 with NYS sales tax. That is less than most of the local parts stores by me. If you're a member check it out. They also sell Techron fuel treatment in 4 packs cheap! Wish they had oil filters then I wouldn't have to go to Azone for anything!

LT5's are notorious for "loosing" oil, both actually burning it and leaking it from alot of places. When I used dino 10w-40 it "used" a bit less but I wanted the "extra" saftey with cold start ups...it takes awhile to get 13.5 qts to operating temp.


Tom

 

OMG! A ZR motor holds 13.5 qts??? I need an oil cooler!!!!!!

 

My next oil change will be to a non API rated synthetic (Redline,Lucas etc) to more closely match what it was born with

 

Just a question.... What does non-API rating have to do with any lube's structure... Does that mean non-petoleum-based???? If so, why not pick the specific alternative type?

gp

 

I think that means that the oil in question did not submitt to the testing standards so it does not get an American Petroleum Institute rating......I think that's right but I'm not 100% sure that is the whole story, there is proly more to it than that!

Gregg, yes 13.5 qts more or less for the whole oiling system, that includes the filter and the oil cooling system also. We have a cooler infront of the radiator so there is a good bit in that part of the system. The pan and filter = 9.5 qts if you change the oil, but we generally let the car sit over night to get it all drained back before opening the pan plug...lots a places for oil to hide in an LT5, otherwise a quickie lube place will only get about 8.5 qts w/filter on a quickie change. We have to be very **** about it and most of us will not let just anyone do even the most basic maintenance on our cars...they are tooo different from a standard bow tie!

The extra saftey I refer to is the oil's lubricity at low temps....syn oil has more lubricity before it gets to proper operating temp( the ideal temp at which the lubricity of the oil is at max ) than a dino oil. More wear occurs while the oil is getting to it's proper operating temp and until the heat is there your oil ain't protecting very well. Any load on the motor should be restricted until proper temp, about 140*, is reached. It's in the owners manual of all vettes....it was in my 72 LT-1's manual & it's in my ZR-1's manual.


Tom

 

GREGGPENN,
I also spoke to The Mobil tech line.He told me to use the 10w-30 ex.It contains more zinc and would be ok to use on my LT1.He also said the 5w could seep thru the seals. The 10W-30 is a little thicker but still good to use according to my owners manual.I agree with you as far as the front line guy is not that knowledgeable.So now I will spend more money on oil to get the EX.This is a ripoff thanks to Mobil.
Thanks again for the info

 

If you are mad at Mobil there are several suppliers out there with just as good a product, maybe better. Your wheels won't fall off if you use something else.

 

I've used Mobil 1 - 10/30 for a number of years now...never any oil consumption or leaks...my last oil change I went with Amsoil XL...it was actually cheaper tham Mobil 1...I beat the snot out of my car at the drag strip and no problems with either oil so far...I could swear my 93 manual calls for 10/30 weight...

 

I switched my 84 from Dino oil to Mobil 1 5w-30 at 110k miles, when I purchased it. It uses a quart every 5-6k miles under conditions that range from daily driving to auto-x'ing and drag racing every chance I get. I am now changing to Amsoil 5w-30 ASL. It is supposed to have plenty of zinc for flat tappet engines-I called and talked to the Amsoil folks . I have had no issues with the Mobil 1 though.

 

Are you sure? No one is responding to my thread asking for opinions/feedback on non-Mobil products!!!!!!!!

 

ttt

 

I don't know how I missed this thread the first time. Synethtics will not cause a leak! Straight from their own site!!!
http://www.mobil1.com/USA-English/Mo...ics/Myths.aspx

Ask a hundred people the same question, get a hundred different answers