jmzo6

For regular street use, no tracking, I usually change at 40% on my 08Z using Mobil 1 5-30 Extended life oil (supposedly good for 15K miles, but at 40% I usually have around 4 to 5K). Sometimes it's not even that low when it gets to one year of time, which I question as well the necessity of. Thoughts?

Dan_the_C5_Man

Never drops below 40%, typically at 5k. Sounds like you are on the right track.

The reality is oil lubricity properties fall sharply at about 1200 miles as compared to new, then level off, but I don't know anyone willing to change their oil every 1200 miles in a DD.

SPDKLZ1

I don't pay a lot of attention to the percentage. I change it every fall before it gets put away or about every 2-3k miles and send it in for a Blackstone analysis for giggles. Nearly my daily with spirited runs each and every time out!

Jesse

h2oskiman

50% changing oil is one off the least expensive preventive maintenance
things you can do Just my 2 cents

MasterDave

Change it once a year, no matter the mileage.

HOXXOH

DD here and never changed until it was 4% or less. Hwy miles (1300 revolutions per mile) aren't killing oil any faster than 2 minutes of idle at 650 RPM, so miles don't mean squat.

08mojo

I change it around 50%, which ironically has worked out to roughly 3,000 miles.

erick_e

I usually send off for a UOA from Blackstone. Recently their recommendation is changing the oil around 10k miles which is usually around 10% remaining on the OLMS.

pewter99

I change it when it gets to 10% or less or it says change oil....why people continue to fight the system is beyond me..tens of thousands of dollars spent on the OLM system and people want to stay with 3mos / 3000 miles. 100's of thousands of miles on C5 and C6's going by the OLM and never an issue due to "old oil" . Probably the same people who don't drive them in the rain or trade it in before it gets "high miles" over 30K


do you 40 or 50% guys throw out the rest of your beer and get a new one at half a glass??


hey its your money

outhouse

With all the people testing their oil, you would think it would show acidity levels getting to high at 5000.
Our motorcycles we do at 3000 but were flat beating them at rpms over 10,000 constantly.
If people are on the gas on this particular car and engine all the time, like tracking it then yes 3000 may be to far.
But on the street you may get much more then 3000. I was cruising down to get a floor jack about 20 miles form home, hell the car cruised at 1500 ish rpm most of the way in 6th at 70mph.

lebvette

Once a year for me. I never get too many miles on it.

REDZED2

Same for me.

LMB-Z

EdsC6Z06

I'm with the once a year folks because I only do about 2500 miles. I do hit the road course now and again, so I like to have fresh oil for those events. Rarely see below 65% on the OLM. I have a shop so it's just the materials on cost.

stefuel

I don't have anything that gets put away for the winter but my riding lawn mower. If I did, the oil would get changed once a year regardless of mileage. I would do it when it came out of mothballs. I would fire it up, take it for a ride to warm up the oil and dump it. That way you know there is no condensation in the oil from sitting for months.

AzDave47

Usually around 30% and 6K miles. I usually do a couple of track days and one or two other performance events. Blackstone Lab oil analysis has always come back in very good shape. I used M1 5W-30 for a while, but once my track day oil temps got to 285* I changed to M1-0W-40.

I just had HCI upgrades and a DeWitts radiator with IOC and it now warms up very quickly and stays around 205 for street driving (oil temp). It has Amsoil 10W-30 in it now.

slappy3347

Me too!

HOXXOH

I fail to understand why people still do the old school annual oil change unless it's to cover their butt for the warranty. Oil doesn't automatically go bad in 365 days.

AzDave47

Running M1 0W-40 in a stock LS7 with some track events, I went 5700 miles and 16 months 0n the oil and the Blackstone report results were as good as prior 4-7K mile changes with less time. I live in a low humidity climate, though.

In more humid areas where it gets cool/cold at night I've seen almost a light sludge form. There I would look to that 12 month annual change.

User Omega

Every 3k miles.