Since your truck has 160k, why not go with the owners manual recomendations? That is, use 10-30 oil and if if any of the following conditions are met, change every 3000 or 3 months, otherwise change 7500 miles or 6 months. (1) Frequent short trips. (2) Dusty conditions. (3) Trailer towing. (4) Extensive idiling (5) Driving more than 50% of the time in hot weather, above 90 deg F.

As far as synthetics and brands, the following article may be if interest.
"Is Your Synthetic Motor Oil Really Synthetic?"
(Reprint of an Article in "Lubricants World" August 2000 by Katherine Bui)
(Involves Mobil-Castrol lawsuit and the definition of synthetic)
http://www.1st-in-synthetics.com/is_..._synthetic.htm

 

also, some say that synthetic wil cause your seals to leak at that high of miles.......

i read an article a while back about some independent testing and they found out that just by changing your filter and the oil in it, that would actually freshen up your oil and be good for up to 2k more, i think

 

Depending on the conditions where one lives.

 

Interesting.
God oil is so confusing, lol.

I think I'll stick to the good ol' 5qt bottle of Pennzoil from Walmart and change it every 3K miles unless the dipstick shows dark or dirty oil :P

Thanks for your help!

 

I've always changed the oil every 2,000 miles. My Dad started me that way when I was a kid, and I just find it easier to check the odometer for even numbers instead of odd number (ie 3K). Every 2000 miles oil & filter and have never blown and engine or had to do a rebuild. I always get a brand name that is on sale (Pennzoil, Valvoline, etc). Been good so far.

 

Yeah, this isn't a topic much worth debating over.

Dino oil change every 3000 oil and filter, you will never have engine problems.

Synthetic change every 5000-6000 miles, you will never have problems.

Oil is cheap. Engine problems are not. Take your pick.

I use amsoil. You only have to change it every 15,000-25,000 miles.
I change it every 6,000-10,000 miles anyway because I'm like that. I never have engine problems.

Fluids are cheaper than the parts they lubricate. Change fluids, and filters, and you will not have problems. Do it. Do it.

 

If you really want to know when to change your oil, go talk to an old mom&pop auto shop. They'll tell you the truth. I do mine @4k everytime. I do this on all my vehicles. If they breakdown it's not the engine breaking down.

As for the feel of the oil, that's a plausible way to tell. Look at the oil you put in your car. Then look at the oil when you change the oil. There is a huge difference in new compared to old.

 

So true, although I go by 5's. Makes everything eaiser. Also, never buy FRAM oil filters!!!! they suck!!
http://minimopar.knizefamily.net/oil....html#champion

 

All I know is when I take out the oil at 2000 miles it always looks black. It probably cost $10 for oil and filter and takes maybe 10 minutes to do (that's with giving the engine a wipe down and everything), it's cheap insurance.

 

I totally agree. Maintnance never hurts anything. I run Synthetic Valvoline (Comes with a reminder sticker) and a Purolator Pure One filter, so thats why I go by the 5,000 mile. I never understand why people spend more money on Mobil 1 or Royal Purple oil. Why not run Pennzoil or Valvoline? Its cheaper, much more plentiful, and I have not seen any evidence why Pennzoil or Valvoline is not as good as RP of M1. Also, Valvoline will garruntee you!