High Mileage Engine - Oil

Hi guys, a "generally speaking" question here. On an engine that's got high miles (nearing 200,000), but is still in good shape mechanically, what would anybody recommend to help keep those miles rolling even longer. I was rolling ideas around in my head - high mileage motor oil, maybe slightly thicker oil to help fill the probably worn bearings, lucas oil additive... this is one of those things though that I wouldn't know if someone was doing more harm than good by using different types or weight oils, etc. Any thoughts? Opinions?

On my Camaro I had 150k on it (305 tbi ) I used the Q high mileage and I highly recommend using Wix or K and N filters on what every you change the oil on.

On my Camaro I had 150k on it (305 tbi ) I used the Q high mileage and I highly recommend using Wix or K and N filters on what every you change the oil on.
Instead of the K&N, I would opt for the Mobil 1. It is made by the same manufacturer, with the same production process, and is less expensive. Here is a quote from an oil filter study to which I will link to after the quote:
"K&N

It's a white Mobil 1 filter with a nut welded to the back. It's made by Champion Labs using what I call their "performance" design instead of the "Ecore". Save the $2-$3 plus shipping and get the Mobil 1."
Link to the webpage:http://www.knizefamily.net/minimopar/oilfilters/opinions.html

Some of you who are familiar with my postings may know I link to that oil filter study on occasion. Imagine my shock when I recently read that there was a new oil filter study done recently to replace the 9 year old study previously in place. In that study, the A C Delco filter came highly rated, and which I had always recommended. Apparently, A C Delco has changed companies, and their quality is not the same as it once was. The funny thing is , the Delco filters are made by the same company that the K&N and Mobil 1 s are, but a different production process is used. If you check that link above, you will see the new oil filter recommendations.

I use Mobil 1 15w50 synthetic with an AC/Delco filter.

Prior to that, I used Castrol GTX 20w50, from startup until 280k miles.

I use Mobil 1 15w50 synthetic with an AC/Delco filter.

Prior to that, I used Castrol GTX 20w50, from startup until 280k miles.


all i use is Castrol GTX in all my vehicles. i was thinking of switching to Mobil 1 in my jeep, but have not

I ran Rotella T for a while due to the flat tappet cam issue (eating cam lobes w/Service M oil) with conventional gasoline engine oil. After that, I now run Mobil 1.

This is gonna sound ignorant, but refresh my memory, The higher the number, the thicker or thinner the oil? (10W vs 5W and so fourth) as of right now I use only factory recommended 10W-30 conventional motor oil in both my truck and Caprice. Penzoil to be exact.

The larger the number, the thicker the oil. When I built my engine in '93, I had decided from the beginning that I'd run the thicker oil in it. Then again, I am in a hot climate and have been throughout this engine's existence. Factory specs 10w30, has for as long as I can remember.

I did break the engine in on straight 30.

You might want to rethink Pennzoil, though. ;)

You might want to rethink Pennzoil, though. ;)
That comment reminds me of the time back in 1988 when I was working in an auto parts store and an oil salesman paid us a visit. He talked with us about the different types of oil and mentioned "shale based oils" and "parrafin based oils". He said the shale based oils were better as they didn't leave the deposits in an engine like the parrafin based oils did, ( and he said that parrafin was a wax and at high operating temps left waxy deposits in an engine ) About two months later I rebuilt a SBC that the former owner had exclusively used Pennzoil in and was amazed at the amount of black deposits underneath the intake manifold as I removed it. I immediately recalled what that salesman told us after seeing that on the underside of the intake :eek:.

That comment reminds me of the time back in 1988 when I was working in an auto parts store and an oil salesman paid us a visit. He talked with us about the different types of oil and mentioned "shale based oils" and "parrafin based oils". He said the shale based oils were better as they didn't leave the deposits in an engine like the parrafin based oils did, ( and he said that parrafin was a wax and at high operating temps left waxy deposits in an engine ) About two months later I rebuilt a SBC that the former owner had exclusively used Pennzoil in and was amazed at the amount of black deposits underneath the intake manifold as I removed it. I immediately recalled what that salesman told us after seeing that on the underside of the intake :eek:.

Exactly my point. The absolute sludgiest engines I've ever seen all ran Pennzoil or Quaker State for the oil. This was back before Pennz/Quaker were one company.

This is gonna sound ignorant, but refresh my memory, The higher the number, the thicker or thinner the oil? (10W vs 5W and so fourth) as of right now I use only factory recommended 10W-30 conventional motor oil in both my truck and Caprice. Penzoil to be exact.

I've used penzoil and castrol 10-30wt in my 1983 had it 17years changed oil every 3,000mi a/c oil filter, after 380,000mi no sludge ,no engine noises no oil leaks and never even had the valve covers off... at the 17year mark 12 ppm hydrocarbons .....also vehicle used 1/2 quart every oil change...first 1,000 replaced oil/filter then at 2,000mi replaced oil/filter...

quaker state oil I don't like...too goopy ....does not flow properly..

back in 1983 10-40wt was recommended but then this was later changed to the 10-30wt...

i recently purchased a oil additive called "restore". ive seen it advertised on spike tv now for a while and have wanted to try it. it is supposed to restore/repair scratches on cylinder walls and compression that has been lost over the years. you just add it to oil when u change it.

rotella i use in my bike and also most truck driver use it. it's long lasting because they can get up to a milion miles out of there trucks. it's really made by shell also.

Goodbye Penzoil then! Y'know that makes sense. My truck has been in my faimly since it was brand new. Always had Penzoil, always had the oil changed at the proper intervals. A few years ago upon opening the valve covers to change the valve seals, I noticed a nice black coating on everything, moreso the cast iron, but everything had it. Not really sludge, but like a film. I guess thats the penzoil for yah. I've seen "high mileage" convention oils with detergants. Wouldn't detergant do more harm than good?

The detergents are what remove the sludge from within the engine. They will not harm the engine.

So not a bad idea to go for it then. I'm on it next oil change. Should I switch from 10W-30 to 10W-40?

No, drop the 10w40 and run. Run far away. And fast.

10w40 has the worst possible viscosity index and it breaks down if you look at it wrong. 20w50 is not bad for a high mileage engine. 10w30 is better for the engine than 10w40.

Wow.... my ATV calls for 10W-40. May have something to do with the fact that is has wet clutch. So if the "W" number is the weight or thickness of the oil, whats the second number indicate (the '30' in 10W-30 for instance)?

The "W" means "Winter", i.e. the oil has the consistency of 10 wt straight oil when it's cold which helps a cold engine start faster. As it heats up, it takes on the consistency of hot 40 wt. oil.

Multi viscosity oil is a misnomer - all oil thins as it heats. 'Multi vis' oils have viscosity index improvers which help it to maintain its viscosity over a wider range of temperatures than a straight oil does. In other words, while straight oils get considerably thinner, a multi vis oil tends to keep its viscosity. So, where a straight 30 oil has a certain viscosity as it's cold, as it heats up it may thin all the way down to a viscosity equivalent to a 10w cold oil, if not more. 10w-30 oil might start out at 10 cold, and keep its consistency to where it's still like a 30 hot or 10 cold.

Wow.... my ATV calls for 10W-40. May have something to do with the fact that is has wet clutch. So if the "W" number is the weight or thickness of the oil, whats the second number indicate (the '30' in 10W-30 for instance)?

perhaps you all forgot or never heard that GM in the early 1980's set out notice that the 10-40wt was not to be used in their engines ....

That was before I was born... but now that you say something I vaguely remember someone sometime saying something about a certain oil that should NEVER be used in GM cars. That must've been it. Anyway... so 20W-50 would be better for higher mileage engines because it's thicker at all temperature levels. I understand now. Thanks!!

perhaps you all forgot or never heard that GM in the early 1980's set out notice that the 10-40wt was not to be used in their engines ....

That was before I was born...

I dunno why I thought you were like 50...

Nah, I'm what my 84 year old grandfather still calls a "youngster"

Nah, I'm what my 84 year old grandfather still calls a "youngster"


I was told to use 20-50wt in my boat engine,it called for 30wt... this is also good for high mileage engines in hot weather...10-40wt lacks the proper lubrication required..


synthetic can take the heat and is great for maintaining its viscosity..

my son had a very worn engine 400mi/quart...I added synthetic drained from my impala when I did an oil change on it ..and the oil consumption dropped to about 600mi/quart...