Synthetic Oil

oil
chevrolet
venture

#1

I am using synthetic oil in my `97 Venture. How often should I change oil in 50/50 (intown and highway) mileage? I know tht synthetic oil is supposed to run longer than regular oil, but not sure how much longer. If I go to 5,000-6,000 miles between changes the oil seems dirty, but has it outlived it usefulness or is the dirt more damaging? Should I change oil filters at 3,000 miles?


#2

The owner’s manual should indicate how often you should change the oil. The interval stays the same for synthetic or regular oil. Synthetic oil allows for more extreme conditions (internal to the engine), and some engines require it. It’s not likely to make much difference in engines that don’t require it.


#3

Trying to convince someone to change their opinion on oil change intervals is like trying to change their opinion on religion. Synthetic oils retain their basic lubrication qualities longer. But oils also have additives to resist sludge and corrosion, and these additives may not last any longer in synthetic than conventional oil. Changing the oil also serves to remove contaminants from the engine.

WIth modern oils and additives, the 3,000 mile oil change is obsolete. Look at your owner’s manual to see what the recommended oil change interval is for your driving style (standard service or rough service). My recommended oil change (2010 Ford Fusion) is 7,500 miles but I change at 5,000 using conventional oil to be safe.

You can’t tell if your oil is worn out by looking at it, but you can send it to a company that does oil analysis and they will tell you how your car is doing.


#4

The part you’re missing is how contaminated the oil is. That part doesn’t change if you use synthetic oil or regular dyno oil.

One last thing…IF you extend the oil change interval while under warranty the manufacturer has every right NOT to honor the warranty on any engine damage


#5

Your oil should look dirty when you change it. Part of the job of the oil is to capture and hold in suspension soot and other contaminants too small to catch with a filter. If the oil is clean when you change it, it’s being changed more often than necessary. Owner’s manual is always the best resource. Many newer vehicles require synthetic oil because they run hotter and synthetic is less likely to sludge under higher temperatures. On your car, I would guess that a 5000 mile change is more than adequate. I used to work for Champion Spark Plug, and our experiments showed that lighter weight oils with viscosity improvers are best on any engine. I’ve found this is best for aircraft engines as well. That’s pretty much the basis for all synthetics nowadays.

but I’m only posting this for the heck of it, because StrongDreams is right. It’s almost impossible to change anyone’s idea about oil change intervals.


#6

You can probably go 5,000 safely, maybe more, but why guess? Get an oil analysis done the next time you change it. It will tell you how contaminated the oil is and if it’s used up or not.

Google “blackstone labs” They will send you containers to ship your oil in for free. You only pay when you get the analysis done.


#7

If you go to the archives on this sight you will find thread hundreds of comments long on just this issue. Even vatican II could not change opionions on Synth vs. Mineral oil. Amen.


#8

I don’t think warranty claims are going to be an issue on a 1997 Venture. It’s already 13 years old.


#9

If my comment was not clear, I would never go longer than the recommended interval, even with synthetic, because of the contamination issue. I might go the full interval with synthetic, and shorter with conventional, but not longer with synthetic.


#10

If you change it yourself and it seems like an easy job to you, do it sooner than later. In the old days, the oil in a Ford always looked clean and GM oil always looked dirty. The word was that you couldn’t tell by the color. In my early days I had a few cars and ny oil changes were done “whenever”.

The only engines that fell apart was the one I ran with no oil. There was this leak and the oil pressure sensor had been disconnected. Oops. It cost me a whole $250 for another engine which cost me $100 to install.

You would spend more these days but you will have to really neglect the oil level to wreck an engine. Do whatever you care to do because it sounds like you will do well if you do anything at all.


#11

Skip the synthetic altogether. Use conventional oil & follow the recommendations (or, in my book, 5K miles, whichever comes first). Your engine won’t know the difference.