Synthetic oil

RambleOnNW wrote:

Turtle n Peeps wrote:

gmcsmoke wrote:
I'd be curious to know how many are getting UOA to prove dino can't make it 5,000 miles and to know when it's time to change the synthetic.

My guess? ZERO. Every time I ask what the UOA said of the people that "know" their oil is bad I never get a response or they say they don't know or don't care. But they sure "know" that their oil is used up. :R

In fact, I would venture to guess from some of the responses in this thread a lot of people on here never had a UOA done or don't even know what a UOA even means.

I've learned one thing; there is a hellofa lot of good oil being thrown away. That keeps a slow economy going good I guess. :B

Well, let's see what your conventional oil UOAs show.

Here's my last synthetic UOA, which is on a 14,000 lb vehicle. Insolubles were up to 0.3% which is higher than what I see on our cars at change time, of 0.2%. Still plenty of life in the oil but this was a once a year change. There were about 20 mountain pass crossings from 1500 to 6000 feet in this interval.

Also note that the Ford V10 requires at least a semi-synthetic 5W-20 oil, conventional oil is not allowed.

Cite your source.

SUKISHORT wrote:
I have a 2005 Dodge 1500. 5.7L Hemi. It has 73000 miles on it. I have kept the oil changes and maint. Very current. I am thinking of changing to a synthetic oil for my next oil change. Is it worth the extra cost from now on? Thanks for the info.

Run whatever 5W-20 you can get the cheapest. Oil is oil.

ib516 wrote:
I bet that kids neighbors love him... :R

I'll take him over our neighbors any day. Drug dealers with ghetto cruisers. Can't wait to retire and move out of here.

Hannibal wrote:
This one looks fairly new. I wonder if it would pass emission testing.

http://www.youtube.com/watch?v=vFMkHLZkDS0

Yup, cams are certainly old school ;)

I bet that kids neighbors love him... :R

This one looks fairly new. I wonder if it would pass emission testing.

http://www.youtube.com/watch?v=vFMkHLZkDS0

NinerBikes wrote:

Nowadays, you can't switch out or modify cams due to pollution control requirements, either by state or by National DOT standards. So Crane cams is a non issue, except on a closed course competition car.

This is not correct. Cam swaps still occur today, even on modern daily driver street cars, even in Houston where the emissions testing requirements are strict.

I didn't think you were supposed to go below 1/2 of the starting TBN number? Or is that just a Cummins thing?

ksss wrote:


climbing steep grades pulling a 20K excavator at 6.5K feet in a plowed field. It was operator error.

I would guess that the same operator error cooked the oil, and thus the valve train. There were probably some very high EGTs and that is all in the head, wouldn't take much to cook some oil. The extreme EGT's are also more likely to cause head issues than coolant temp, thou both aren't good.

Blackstone wrote:
The TBN was strong 4.1 plenty of additive remaining.

You do know what this means don't you?

GM rates 5W40 for temps below 0 degrees and up to 90 degrees. Severe duty has nothing to do with the grade oil, only the ambient air temperatures under which the engine will be operated.

It seems contradictory to talk about oil temps of 245 degrees and then wanting to use a 5W40 motor oil. If your oil temp is truly above specs then I would fix the problem with a supplemental oil cooler or a larger sump or some other measure.

Oil temperature is not the problem but the protection that the oil actually provides for moving parts when under pressure, as with the main bearings. This is where multi-grade oils are less effective and the lower the weight the greater the problem. By the way the fleet truckers are moving to 10W30 for their engines and not a 5W30 oil. Cummins uses and recommends using Valvoline Premium Blue dino oil in its diesel engines and this oil has an exceptional additive mixture.

ALL SAE API rated oils have passed tests in terms of the pressure that the oil can withstand at normal operating temperatures without metal to metal contact.
This testing has also shown that polymer shearing does occur when a multi-grade oil passes through tiny apertures at high pressure and when this happens the lubricity of the oil is greatly degraded - as with oil entering main bearing journals.

What is also vastly different with diesel engines besides the introduction of soot and unburned diesel fuel into the crankcase is the high percentage of each gallon of oil that consists of additives. 25% of a gallon of oil is additives and these are not going to be as effective at 25,000 miles as they were at 5,000 miles.

I can change out the dino oil every 7500 miles and get all the soot and sludge out of the crankcase and I can put in new oil with a new batch of additives, or for the same cost I can use synthetic oil and change it out every 20,000 miles. To me the advantages of dino oil with a diesel engine are obvious in this situation.