[Graymist]

How is dyno testing done, and what information does it reveal ? How does one interpret the results of an oil sample test ? Does one do the interpretation oneself, or is it done by the sample testers ? How much do both these tests cost ?

Also, when buying a used truck, how does one determine the veracity of all the mechanical specs that are listed ?

[GMAN]

Some of the things a dyno will tell you is torque, hp on the ground, fuel distribution, oil pressure, head pressure, etc., It will tell you what is going on with the engine at that time and should tell you the general condition of the engine. An oil analysis will reveal any excessive wear going on in the engine. It is a good way to check out a possible engine component failure before the fact. It enables you to replace components before they fail and cause potential damage to the engine. The oil sample is usually done at the same time you do an oil change, but you can have one done at any time. The last oil analysis I had done cost $14.95.

[Red Clay Rambler]

Speedco will analyze your oil sample while you wait, only takes about 15 minutes. They give you a print-out of the results which will explain the different categories tested and what the results mean, what might be causing any problem readings.

[geomon]

If a used truck dealer (or individual seller) did a recent oil change then an oil analysis done as a way to verify the condition of the engine would be worthless...is this true?

Would you be able to tell with an oil analysis if the oil was just recently changed?

[GMAN]

You need to know about how many miles are on the current oil change. If the oil has just been changed, you won't find much useful information with an oil analysis. They usually ask number of miles since your last oil change and type of oil used.

The dyno can be performed at most of the major engine distributors and truck dealers. Some dealers send them out to be done.

[allan5oh]

Originally Posted by Red Clay Rambler

Speedco will analyze your oil sample while you wait, only takes about 15 minutes. They give you a print-out of the results which will explain the different categories tested and what the results mean, what might be causing any problem readings.

generally those oil samples are not as accurate as sending into a lab.

[Red Clay Rambler]

What does a lab do differently?

[allan5oh]

They are better trained for the equipment they use, and labs can generally test for more things.

[Graymist]

Originally Posted by GMAN

You need to know about how many miles are on the current oil change. If the oil has just been changed, you won't find much useful information with an oil analysis. They usually ask number of miles since your last oil change and type of oil used.

In that case, what should be the minimum nuber of miles on an oil change, for a sample test to yield proper results ?

[arky]

I should leave this to GMAN and some of the more experienced guys but it's my understanding that the best results come by having an oil sample done at about the same time (same # of miles) over a period of time. For example you would have your oil sampled after you've put 10,000 miles on your oil change. Do this for 3 or 4 times and compare the results. Then a year later or whenever you can get the sample done and compare it to the original results to see what might be changing.

I'm sure that an initial oil sample can tell you many things, but I'm not sure you could make any definite conclusions from one sample alone..unless of course they found something extremely out of spec.

I would think a minimum of 5,000 miles to get a good idea.

Arky