I know these new Mobil one full synthetic oils are slated to run 15000 miles between changes etc etc. I have started to change my oil in my 2002 C5 z51 with 160k miles once a year. I only run around 2000-2500 miles a year and use mobile one high mileage full synthetic. My oil life tracker usually stays above 80% or even more. I've heard that oil does not corrode just sitting in the engine but I am unsure. Is this enough or should I change it more often? Thanks

 

Mobil 1 says to change oil at least once a year regardless of mileage.

 

Back when I was living in MI with parents in the late 50's/early 60's our neighbor was a Ford Executive/ engineering division. He had a company car and was told to drive it for 3 years (1958 to 1961) w/o changing the oil. Only the oil filter and added oil when needed. He traveled 3 states for Ford. What he told me is when they broke down the engine the wear was minimal. Nothing unusual. Is the oil changing a hype especially with the new oils? You decide. I still change the oil every year or 5000 miles whatever comes first.

 

that's an interesting story! I will continue to change every year regardless of mileage and in the event I reach closer to 4k I will change then as well. Thanks!

 

In my opinion changing synthetic oil more than once a year is a waste unless your mileage exceeds 15k... Once a year mileage notwithstanding...

 

With mostly highway miles, my OLM will let me go 12k - 13k miles between changes. I change my oil at 10k miles and at the end of season before hibernation. (I will change oil sooner if OLM suggests it) Z06 is over 290k miles and truck is around 180k miles.

 

I couldn't sleep at night if I changed my oil before 15k. Car sat out side for 5yers in storage. Checked Oil Looked good started it put 10k before I changed it. And that was a tuff decision to change it.

Everybody keep making them oil companies rich.

353k on my other car cheapest oil for 15yrs. 15 to 20k oil change intervals. Oil was so cheap one qt to another had different oil colors.

The only reason why I'm not driving it is the frame cracked in half. Lol

Not telling what do just my experience.

 

You and 3sacrowd are living proof that most engines today are bulletproof and with a minimum of care will last a long time... I only put about 500 miles on a fresh synthetic oil change so skipped an entire year...

 

With proper maintenance, most engines will last a long time. I had a 1981 Coupe Deville that went 173k miles. The only reason it stopped running is I murdered it. The idiot light for coolant temp burned out and my radiator plugged. I overheated that crap out of it. I prefer gauges to lights because of that. I changed my oil more often then.

I worked for GM for 28 years and learned a bit about engine testing. (I worked in a foundry casting blocks and heads and often met with Design Release Engineers) The LS engines were designed to go 250k miles. (Chassis is designed for 400k BTW) The OLM was developed to help with the decision on when to change oil and has been extensively tested.

I'm a firm believer in synthetic oils. I also think that my driving habits lend to oil life longevity. Nearly every time I drive, the oil gets to full operating temperature so moisture isn't a big factor. Also, highway driving is very easy on an engine. If I believe the conditions warrant (autocross etc) or OLM indicates sooner than 10k miles, I don't hesitate to change the oil. I also change my oil before storage to get any combustion byproducts cleared out. That is what makes ME happy based on people I've talked with over the years. Do what you are comfortable with. I share my experiences so others can formulate their own opinions.

 

We have several engineers in our club from GM,FCA, and Ford and they all say the synthetic oils will last longer than 15K mile, it is the additives that break down and require the oil change. Also they all agreed that stop and go traffic was the hardest on the additives, not getting to operating temps, and all changed their oil before putting the Corvette to bed for the winter. FWIW

 

Just my experience, and opinion, but it's hard to argue your points. The synthetic oils of today are vastly superior to the oils of the 1960s and 1970s. Back then, I'd change my oil and filter every 3,000 miles, and had very good results. Even though today's engines run hotter by design, and also have much higher redlines/rpm capabilities, I have no problem going 6,000 miles on Mobil1 in my C5. I also believe a magnetic drain plug will help your filter and oil pump last longer. So I guess I'd consider doing what one Forum member said, and that would be changing just the filter every 5,000-6,000 miles, and the oil and filter at 10,000-12,000 miles.

 

Not to highjack this post but will it harm engine to go from regular oil to full synthetic, my previous owner used non Mobil synthetic and was planning to go back with Mobil synthetic, any issue doing this. Thanks

 

Appsolutely not. Perfectly fine and safe.

And this is the oil filter I'm been using on all my cars and all my friends cars. To long ago to remember when I started using it.

 

To add to Helga203's reply, you can add synthetic, change over to synthetic, mix with dino oil, all safely and without issues...

 

When the DIC says to change it.

 

Dame i missed that. I thought it meant to check oil not. Change.

 

If you're not running the car that frequently you should AT LEAST start/run it every month to 6 weeks and let the oil temp get above 212 in order to boil off any water that may have collected due to condensation. If will also ensure that lubricated parts don't get too dry. As far as changing it, yearly isn't a terrible idea, but if you're boiling off the moisture regularly you're probably ok stretching it longer.

 

Personally, I wouldn't be throwing away perfectly good oil changing it once a year like that.

 

I have heard that going from regular to synthetic may present some oil leaks as the synthetic is smaller at molecular level or something like that. But in your case it's fine. Syntheric is what the engine is designed for so it will be better actually. Kind of like how your c5 will run off of 87 octane, but it is designed for higher octane fuel and will run better with it.

 

well sure. That’s when I check it. After I change it.
Seriously I change with Mobile 1 about every 15,000 miles. Oil I drain is clean and clear. Use the old oil in lawn mower and other general lube. Daily driver (only car) 130k miles. Uses no oil between changes. Seems to run better now than 16 years ago. It is particular about fuel. Use 93 octane no ethanol whenever possible. Clatters on 10% and hard acceleration. 2004 CE convertible A4.