switched to synthetic

04silverado1500 · January 30, 2007

hey guys i have an 04 silv. 1500 5.3 Z-71 4x4 as the name states. i was wondering how many miles i can safely go on fully synthetic mobile 1 oil. i was thinking i would just go with 3-5k on the first change and check it regularly to make sure its not consuming any oil during the switch. also from there on how long should i go, im not worried about the cost its cheap insurance and this truck has to last so changing it every 5k instead of 15k if its safer is no biggy in my book. by the way the truck has 49.5k on it and will have 51k on it when i do the frst change to synthetic.

i also have another question when i lay into my brakes they are fine but after hard braking when i let off it almost feels like a real short vibration like it sticking and then letting off. Does anyone know what this is i would like to figure it out. oh yea and it may sound stupid but i know its not the pedal itself becasue it only happens when the truck is on and driving not when i pump the pedal in the garage or something. open to all opinions on these topics and o yea dont start a big flame war over oil type or brand thanks.

mcreyaufmiller · January 31, 2007

For the brake problem, I would look to sticking calipers, take it back to the dealer and tell them what is happening and they should fix it under warranty. As for the synthetic, I usually run it for 6k, it has worked well for my truck. My work truck, I use the 15k stuff and run it all of those miles, only way I can keep from changing it every 2 weeks.

03blackburb · February 1, 2007

To really know for sure how long your oil is good for you have to send it out for anylasis. Blackstone Labs is one place. Typically full synthetic can easily go well over 20 K.

I ususally do a complete drain somewhere around 28K, but change the filter about every 7K. It never gets to the point where it is black.

04silverado1500 · February 1, 2007

yea thats what i was thinking about the sticking calipers thing although sadly my truck is not under wrrenty so my speed that just went out cost me 367 and i might just pull off the wheels and take a look at the brakes myself

mcreyaufmiller · February 2, 2007

20k is a lot for my taste. I am using the Mobil 1 15k stuff in my work truck. That is only because I want more than 1 week between changes.

Ductape · February 2, 2007

Main reason oil needs changing is to remove contaminants and replenish additives. Syn gets dirty no less than conventional. Oil analysis is the only way to really know what you can do for extending change intervals.

I use syn -just to get better cold start and high temp protection- but stick with the regular change intervals.

My .02

DT

03blackburb · February 2, 2007

If you ever are around someone who works with either big trucks or big engines, ask them how often they do a complete drain on the oil and what criterial is used to say when to do the drain. You would really be suprised at what they use for a change indicator and typically what the drain intervals are. the main thin is you canNOT visually tell if the oil needs to be changed unless you have a chocolate milk shake and if so you other problems. You need to have a sample lab tested.

Here is a link to a test done a while back: http://neptune.spacebears.com/cars/stories/mobil1.html

mcreyaufmiller · February 2, 2007

The difference between the "big trucks" or "big engines" and our trucks is the ammount of oil used. My Cummings uses 14 quarts, longer change intervals, my benz uses 10 quarts, longer change intervals. Our Chevys use 5 quarts, not so long. If you add a larger oil pan and get more volume, than I can see the longer change periods. The idea being that you have more oil to dilute, the longer the change intervals. The other difference between out Chevys and the big trucks is the run time. The big ones rarley get turned off. this is better for the engine in the long run. our trucks are turned on and off, they are run at idle and in city traffic, the big trucks run all of the time.

But hey, do what you want, it's your money to spend!

marko · February 4, 2007

Does your truck have the 'message center'? That will tell you when to change the oil. My synthetic lasts about 15000km between changes, so about 10k miles. You should consider how hard your driving is. If you drove exclusively long-haul highway miles you could go longer.