Speaking of oil motor oil again--more on Mobil 1 please

[Farmer Brown]

I might give that a try after Runners good endoresments. I think it's good for more miles between changes?

Speaking of oil changes, was talking to a Roadway truck driver when here on a delivery. Looking at his old Mack with over a million miles on same engine. Ask how often oil change. Said don't really change but have a drip system on them that drips out about a qt every thousand. Drips into a line that runs to fuel tank. So they just add a qt every thousand miles and change filters every so often. Says that way no problems with gettng rid of all the used oil. I know Yellow Freight used to drain the oil and walk around and dump it into fuel tank to get rid of it. May not now---- Must work----over a million on an engine. FB

[scott]

in a previous life I was a crew chief for endurance sports cars....we ran 6,12 and 24 hour races .... mobil 1 is good stuff ... i've had a lot of other oils "give up" in the middle of a race ... there was a team with some big oil money behind them (not mobil) .... they would use the sponsors quart bottles and fill them with mobil 1 .....

[mohillbilly]

Mobil 1 oils and lubricants are recommended in literally almost all industrial manufacturers gearboxes and drives. Have had excellent results with them, even in 500 degree temps I dont think you will go wring with mobil. Never run it in a truck or car, but if performs well in harsh industrial conditions, I am sure it will do good for you.

[Runners]

One thing about those big trucks, they don't hold QUARTS, they hold sevaral GALLONS of oil. It stays cooler and lasts longer than it would in a car.

I probably should have added, we run Mobil 1 in our I/O merc cruiser's engine and 80w90 Mobil 1 in the lower unit. The 200rpm increase didn't happen over time, it was immediately after we changed the oil in the lower unit.

Way back when I had a '52 GMC panel truck with a 261cid straight six engine, a guy told me to flush the engine with fuel oil between changes. This engine was not original to the truck, and the filter was a "bypass oil filter", canister type. As a rule, I ALWAYS flush the oil with fuel oil or "Sea Foam" before I switch/start using Mobil 1. (and I never mix oils.... duh!)

a. The engine must be COLD - ie., not run since the day before.
b. drain all oil, change filter and refill with fuel oil.
c. start and run engine 5 minutes (or less), watching oil pressure CAREFULLY, if it can't get lubrication, SHUT IT DOWN & drain it. The mains are probably too loose and it's time for 20w50.... if it won't throw it out the seals.
d. completely drain oil, change filter (again, use a GOOD one), and put in Mobil 1, 10w30 or 10w40 or whatever you prefer (20w50?)
e. Check the oil after a month or 1000 miles and see if it's getting thrown, getting dark fast (rings, valve guides, excessive engine wear), or the viscosity is changing (ie. THICKENING from previous STP or Teflon or other oil treatments).

Assuming it's a happy engine, I'll change it around 12-15k, with filter changes (Fram....) about every 5k.


Oh, that old 261 engine... I lost the oil pump, called a freak accident. Rebuilt the engine, and eventually sold it with over 80k miles. For a 1 1/2 ton truck, getting 16-18mpg was a dream back then. It had an "open crankcase", and it wouldn't burn Mobil 1 - but would burn just about anything else... you could literally SEE the oily smoke coming out the breather pipe when the engine was hot.

We also had lots of VWs back then. Mobil 1 was in the 5w30 variety only, and unlike other oils, the VWs didn't burn it - they'd throw it! Same 10% increase in mpg, but unless you sealed up every little leak, you'd lose your mpg savings in oil leaks. Those air cooled VWs ran really hot, and few oils lasted long in them (or remained in them long...)

I've tied Amsoil (sp), Castrol and a few other synthetics, but it seems like they break down (thicken) with heat and age faster than Mobil 1. There might be a better engine oil out there - I'll try it if there is. But I'll never use "oil treatments" again (...aren't they just thickening agents?).

As far as heavy gear lubes, Mobil 1 beats them all hands down, I even use the bearing grease on all the zerk fittings. But, the difference with the Mobil 1 heavy gear lubes has always been immediate in more speed, or less fuel consumption, less noise & cooler running.

This is my personal experience, I'm not an expert. But the stuff about the fuel oil (or sea foam) flush I got from an old "head wrench" for diesel trucks. I use Sea Foam now for the flush, just add it to the oil before I change it. Again, the engine MUST be COLD - read the instructions!

[comfortablynumb]

you have to be carefull with the diesel flush trick... do it to well and you dammage the main berings.

once you flush and you put your new oil in your well advised to IDLE the engine for about 30 min to let he oil work back into the mains where it should be and get the residual diesel out of all the little cracks it settled in.

myself when I flush with diesel its a 2 oil change deal, the flush part, then clean cheapo oil and filter, then in about 100 miles another drain and fill with the good oil & filter.
once you flush you still have loose bits and sludge that needs removed, youll note that a few hours after you flush your new pretty oil is black again (sometimes).

when I got my old ford the oil was horrid and black like molassas.... I changed the oil 4 times till it would remain clean past 100 miles. we just cracked the engine to put on a new head, and its impressivly clean in there. not at all what i expected since the old oil was so bad.
clean engine= happy engine.

[Hip_Shot_Hanna]

there is no reason to " flush " a diesel engine , all diesel oils are high detergent ,low viscosity oils 10W 30w is usual ,
Mercedes Benz now recomend 90.000 mile oil changes when using synthetic oils on their V8 and V10 diesels, and a million miles is not unusual , only abused engines break before a million comes up .

[Farmer Brown]

Sea Foam, now that's the stuff! Saved an engine teardown on a Crown Vic last yr. Oil passages to timing chains and top end got plugged with goo. Added a cup and within 5 miles did th job. Then changed oil and good since. Flushed my old 300 6cyl Ford engine by adding last 50 miles before a change just a few weeks back. Stopped a sometimes sticky lifter. Bigger trucks oil capacity?? I've got a 855 Cummins with 44 qts and a Cat 3406 on the drill with 48. Use 5 gallon pails and a hand pump to fill. Have to take out a loan to change nowdays------