Double oil change....

It works, but if your really, really concerned about it, just cut your normal change interval in half. That discoloring isn't hurting anything. A brand new diesel looks black in a couple hours.

Personally I think the extra money would be better spent putting in synthetic. I have used Mobil 1 since it was first introduced. Use Casrol Syntec if you prefer their brand.

~Perk> This is pretty amazing ! but maybe some of you already do it. A buddy of

I had posted a few weeks ago about the synthetics. and from what I kind of understood from others was it wouldn't do much good in my truck with

170,000 on it. now it might be ok on the Tahoe it just turned 80,000. what is your thoughts? and maybe the double change is just good once in a while. because maybe the discolor doen't mean much. but when i ran it through the Tahoe twice, why would it stay so much cleaner so long? what is all the black in the Z71 oil with one change? like I said my truck only has about 400 miles since I changed it the last time and it's already black. the Tahoe has about 1500 miles on it after two back to back changes. why is it not black ? that is 3 times as many miles.....?=BF? Thanks

First... it certainlly would not hurt to change it twice.... three time, ten times, one hundred times. They question is, does this really make a difference?

Your oil filter is designed to filter most debris from the oil. Good ones do a very good job of this and from what I understand, by-pass filters do a better job. But in that your oil filer is doing its job all the way down to a few microns, I don't see much of a reason to change the oil twice back to back. I'd say even better then changing to synth would be to buy the most expensive oil filter you can. It's bound to cost less then changing the oil twice so close apart.

What your probably seeing in the oil is simply very fine carbon particals. They are suspended in the oil and... IMHO, really don't do much damage to the engine. Larger particals, lack of deterginent, and the breaking down of the oil probably leads to more problems.

But you know... in the end, no matter what you do... you need to stick with what makes you feel best. For some it's running synth. For some it's running dino. For others it's buying a great filter. If speanding a little more on two changes make you feel better... then, please, do it.

170,000 on it. now it might be ok on the Tahoe it just turned 80,000. what is your thoughts? and maybe the double change is just good once in a while. because maybe the discolor doen't mean much. but when i ran it through the Tahoe twice, why would it stay so much cleaner so long? what is all the black in the Z71 oil with one change? like I said my truck only has about 400 miles since I changed it the last time and it's already black. the Tahoe has about 1500 miles on it after two back to back changes. why is it not black ? that is 3 times as many miles.....?¿? Thanks

OK, so (a) you work for an oil change place or (b) this is a not so clever advertising ploy orchestrated by the oil change industry. Your industry has already fooled a lot of people into thinking that they need to change their oil every 3,00o miles and no doubt there will be people that believe this one and now will change their oil ever 400 miles and you will get even more of their money.

Bud Lite

I switched to Synthetic with engines that had at least 70,000 on them but I knew the engines were clean. Back before that I often used oil rated for diesel engines (Rotilla or Delo). I don't believe that synthetics have any more detergents than they do.

Used to be that gaskets gave out when using synthetics. Now they are totally compatible.

I was pulling trailers over Colorado passes with a Chevy with a 450 cu. in engine. It would be down almost a quart after pulling over a 12,000 foot pass. When I would open the filler cap fumes would come out. The oil was vaporizing. I even tried using 15W50. Then Mobil 1 came out, only in 5W20 to start with. I tried it. No more noticeable oil usage. Only thing I really noted on those carburetor engines was that I had to turn the idle down after switching to Mobil 1. Now of course I use recommended viscosity, either 5W30 or 0W30 in my gas engines.

Anyway, the bottom line is that under severe usage is where the synthetics really show their stuff. Normal oils began to break down at about 350 degrees. Synthetic is good to over 700. There may be spots in yours engines that get over 350. Shear strength is also superior to conventional oils. Sludge in the crankcase is the old oil breaking down. You don't see that with synthetics.

Many synthetics are not worth the cost. Figure it out. Just how much do you spend on oil over the life of the vehicle. Oil is one of the lower expenses. If it makes the engine last longer and if you get a little better mileage, so much the better.

Conventional oils are a lot better than they were when Mobil 1 first came on the market. Then again, Mobil 1 is better too.

maybe I wasn't very clear when I said changing it every 400 miles. what I was saying is I changed my oil in my truck 400 miles ago and it's black. My Tahoe I ran about 500 or so after the first change then changed it again. now the Tahoe has 1500 miles since the second change and the oil looks like i changed it today. This information I got from a guy who finished second in points in Nascar Weekly series In a late Model (Heartland region) it's just what he does to his race cars it wasn't anything I heard from an oil company. what filters would you all recommend? Thanks Bob

Mobil 1 filters.

Doc

>

AMSOIL Super Duty Filters:

Also, a Dual By-pass system would do you more good as well.

I haven't found anyone who sells mobil 1 oil filters around here.. granted I haven't looked real hard.. but i use mobil 1 oil and wix filters.

Adair

I've never heard a good explanation but some vehicles just seem to dirty up the oil quickly and others don't. My S-10 oil will still be honey colored (but darker then when fresh) on the dipstick even after several thousand miles. My old 69 Firebird was the same way. But my Caprice would be dirty after less then a 1000 miles as would my full sized Blazer. Except for the Caprice (bad valve seals), they all went way past 100K. The S-10 is at 155K now and has some of the cleanest used oil I've seen in a long time and that's with Synthetic in it.

Thanks for the responses. I think I am going to switch to synthetics in the Tahoe with 80 k and If I understand correctly it might not be worth the money to spend on the Z71 with 170,000? or will the synthetics help the Truck? Thanks again ! Bob