I run synthetic, oil looks fine, I only drive the car maybe a thousand miles a year at most, how long does oil stay good for? I figure it should be changed every six months or so?

 

Only way to really know is with an oil test. 6 months should be ok with the small amount of milage you put on. Patman will definatly have some more insight on this
With synthetic the oil will sometimes outlast the filter. Search for Patman and synthetic or something like that, it should turn up lots on this

 

There are alot of opinions on what synthetic brand is the best and what duration they can be run to. Most people don't realize there is NO best synthetic for each and every engine/usage. There is an iteresting site www.neptune.spacebears.com where they conduct an oil life analysis on several diffrent brands of synthetics in one test vehicle. The vehicle just happens to be an LS-1 equipped Z-28! They have alot of good info on oil testing, results from past tests etc. I personally recommend RedLine Synthetics. I love their product and have seen great results at long extended drain intervals in my 96 Z-28.

 

http://neptune.spacebears.com/
No www _

 

At leasy 7500 miles with a good filter in my opinion. It's great oil.

 

does anyone knwo how many miles a bosch oil filter should be used for? and which oil filter should be able to handle up to 5-7k miles?
thanks!

 

I use an STP 1 quart filter for a sm block that sits level with the pan.
I bought a bunch of them at Autozone. I think the # is 535 or 585.
I'll check the ones I have at work.
Don't have any numbers but mI figure a larger filter is good for longer oil changes

 

Just out of laziness I ran mobil 1 in my lt1 for about 2 years, which I would say was roughly 30,000+ hard miles. I had to top it off every once in a while due to leaking. This was also with a fram filter, which from comparisons I've seen is not the best. Hope that helps.

Jon

 

why not just change it at 3000 miles? Its good preventative maintenance and its not very hard. i would rather spend $20 every 3 months than have to pay for an engine rebuild...

 

i only drive my car ~5k a year so i change it every couple months, use M1 or German Castrol with a K&N Filter

 

The 1 quart STP filter is number S373.

 

Did you have the oil tested to see if it was doing it's job anymore?
3K mile changes are really actually very wasteful and there is evidence to support they are not even better for the engine, people who sample a few times through the course of an oil change interval are finding that wear is higher at first then drops a bit and levels off before it again rises once the oil begins to actually get dirty or wear out(shear down or oxidize and thicken). Will 3K mile changes do damage no but just think saying they are best is wrong. For the record when I talk about oil I do so based on reading actual data about wear metal content in used oil. Everyone wants dyno numbers or track times for power mods yet most talk up one oil or another with no actual data to support their claims, which is just stupid. Oil analysis can tell you how an oil is actually doing, by measuring how much wear metal is in it, I find it simply amazing that people here try to disagree with it or even choose to ignore it. I do most of my reading on the subject at http://theoildrop.server101.com/cgi/ultimatebb.cgi Patman who gets mentioned in about every oil post on this board is a moderator over there and has helped amass a wealth of info on LT1 and LS1 oil perfomance.

 

so are you saying that it is better to change oil at 10000 miles than 3000 miles?

 

Only way to know under your conditions would be to sample it and have it analysed, 10K might be a bit much but just to make a point I believe the LS1s are all the way up to 15K as the recommended interval, it may not be the absolute best as far as longevity but isn't particularly bad as long as you keep it clean. Hell read your owners manual my b-bodies with the exact same rotating assembly as the f-body call for intervals up to 7500 and they are not specing synthetic for that. The 3K thing is just years of brainwashing and marketting by dealer service departments and JiffyLube. I actually recently saw liturature for a 60seomething Caddy which called for every 60 days or 6000miles on the oil change, engines and oil have each come a long ways since then. One of the biggest reasons oil can be run longer these days is actuallu fuel injection, carbs end up diluting the oil with fuel and filling it with carbon. Most people should be able to easily get away with 5K intervals but testing is the only way to be sure, there are lots of options there anything from buying a package of basic tests for $10 apiece to in depth lab work and proffesional analysis of the results for $35 a crack.