I have a question about oils that you might help me with. I Recently changed oil and I thought I would try some mobil 1. I got a jug of 10w 30 high mileage and a filter. I was previously using vr1 20/50 but I concerned it was too thick. After the change, I used a quart in only 150-200 miles. I don't see any leaks or smoke out the tailpipes. Was this a bad idea? Anyone have a similar experience?

 

if you were happy with the VR1 why didnt you just get the 10W30 version, I had been using the 20W50 and having read articles here switched to the 10W30, it's available on Amazon

 

I can't find VR 1 10 / 30 here locally. I guess I could order it, but its not on the shelf. Maybe I have a bigger problem than just the type of oil. I hope not!

 

correct i could not find it on the shelf either hence got it from amazon

 

I tried synthetic in my old junky pickup and didn't have any problems so I gave it a try.

 

I went from VR1 10W-30 to M1 0W-40 with no issue.

 

0-40 ? What's the zinc level on that? Ill give it try if it will work on a flat tappet.

 

1000 PPM Phosphorous, 1100 PPM Zinc. Group IV TRUE synthetic. About $25 a 5 Quart container @ Walmart. Good stuff!!!

 

I have mobil 1 0W30 in my 74 right now and no issues.

With a oil analysis my 96 Silverado can go 12 to 13,000 miles on one oil change.
My 03 Silverado Duramax has gone 19,000 miles with a filter at 10,000
My wifes 05 Cavalier on the other hand does not seem to like Mobile 1 to much.

Haven't had the car long enough to put enough miles on to test it yet.

 

The 0W-30 is a Group III basestock, NOT a Group IV true synthetic, with only 650 PPM phosphorous and 750 PPM Zinc. I wouldn't recommend it with even a stock flat tappet. Here is a chart.

http://www.mobiloil.com/USA-English/...duct_Guide.pdf

 

If you have a flat tappet cammed engine, I would use Mobil 1 15W-50 with a flat tappet cam (1,200 PPM ZDDP and specifically recommended by Mobil for this application-Read the oil sticky) which I did for many years before I rebuilt the L-82 this past spring 2014 with a roller cam. ALL Mobil 1 grades (EXCEPT the 2 grades below) like almost all mass market oils sold in the US ONLY that are labelled "synthetic" are NOT true Group IV synthetics but are highly refined conventional oils and are now considered Group III+ oils. I believe that Valvoline Racing Synthetic (not sure) is a group III+ highly refined conventional oil as well. The only US marketed "synthetics" sold here that are true Group IV synthetics are Redline, Amsoil, Royal Purple, AND Mobil 1 0W-40 European Formula and Mobil 1 5W-50 Porsche Specification. Mobil 1 0W-40 (1,000 PPM ZDDP) is probably the best bargain out there for a true group IV synthetic @$25 for 5 Qts @ Walmart-can't beat the price/value equation. I am about to switch the L-82 355 with roller cam to Mobil 1 0W-40 Euro Formula after about 650 miles on the new motor from Driven 15W-50 conventional for the breakin period. Unless you drive the car when the temp is under 20 degrees (that temp is actually for 20W-50 grades-see chart below) , a 15W-50 grade oil is perfectly fine and you are probably good to go with Mobil 1 0W-40 with a flat tappet cam as well. Below is the oil chart directly from my 78 C3 owner's manual when oils were conventional only and inferior to the oils today:

 

If you want to use a 0W-30 take a look at the Castrol European oil.

I use it in my Mazda 2, Outback and Volvo C70.
Autozone sells it.

 

Getting back to my original question, I pulled the plugs today and found all of them oil fouled. So i did a compression test. On a cold engine 5 were at 210 and 3 at 220 psi. Can I rule out a ring problem ? Is it possible to loose ring seal on a warm engine? all plugs look basically the same, so im thinking, pvc valve ingesting oil (I hope) or an intake gasket failure.Is there any place else oil could get injested into all 8 cylinders ? I can't believe changing oil type would cause such a drastic change. Any ideas would be greatly appreciated.

 

I also live in S/W PA and use VR1 10-30. My local NAPA orders it for me, by the case.

 

Thoughts on using the M1 0-40 in a high mileage L46?

I have been using Shell Rotella.


Thanks, Bill

 

If your asking my opinion I believe the Mobil 1 0W-40 is a better option. I lost a forged 302 with under 5000 miles never redlined. 3 wiped lobes with Rotella after being a faithful customer for 30 years.

 

Can somebody throw me a bone here?

 

Sure. Don't ask questions mentioning oil. You'll never get a straight answer or any sort of consensus.

Speaking of that, there's no real advantage in using synthetics in an engine that was designed for them in the first place unless you extend the change interval to mitigate the higher price.

Now watch the fur fly.

 

Im not looking for a fight, just want to know where my oil is going.

 

Leak down test may tell you more. Valve seals, bad PCV valve maybe.