I'm reading "101 Projects For Your Corvette" By: Richard Newton and he says that we don't need to change the oil until 7,500 miles. Plus he go's on to say that, "Very few people have the qualifications to actually judge the quality of an oil." This is do to the constant changing of the formulations.. So which is the better brand, and how can we tell as a consumer??? Any thoughts on this ???

 

Oil is cheap, engines aren't. When in doubt, change the oil.

 

Don't get me wrong, I change my oil religiously, just want vetters thoughts on what this BOOK says.....

 

Over 7,000 miles seems like alot. I do it every 3,000. Im sure its ok to due it if the book says so but its safe insurance to do it sooner. Judging oil. Well to an extent but the basic is if its dirty its doing its job and it needs to be changed. If it looks clean, there may be a problem. Thats judgmental enough for me.

 

Richard Newton is correct on both counts, technically, But I am more in agreement with "when in doubt, change the oil", and "oil is cheap, engines aren't".

 

If you do 7500 miles in a year that's probably just fine.

 

Most of us do not put a lot of miles on our Vettes. I put less than 6000 miles a year but I change the oil at least twice a year. Not because it is dirty but because the engine sweats internally and the condensation that naturally occurs is an enemy that needs to be removed. I change oil every 3000 miles on everything I drive and I use an oil that meets the manufacturers recommendations. I use a dino oil in everything but the Vette and use syn in it because that is what it came with new and that is what is recommended. I also change the filter at every oil change. I have been doing this for over 45 years and have no reason to change now. The book is making recommendations and that is what it is, a recommendation; I like to err on the conservative side. Just my 2 cents worth that has worked extremely well for me!
Bernie

 

there are a lot of parameters that determine oil life for me.
1. I mix half synthetic oil with regular mineral based oil, and it runs fine. synthetics cut friction, great for higher heat environments.
2. I also change my oil when it looks dirty whenever I've determined that.
3. I also change the oil before summer and after summer. summer here lasts 6 months sometimes.
4. If I have a problem with my fuel system, as I had a short time ago, I change the oil after it's fixed.
5. If the summer is extremely hot, I run full synthetic oil.
Oil is the lifeblood of your engine. during the summer, it gets to 118 degrees here in Phoenix, and sometimes I see the engine oil temp approach 255 in traffic. The oil gets changed if it hits 260. I remember the summer it was 120 degrees outside, and when I got home it had hit 260 3 times. lucky it was a friday night, and I changed it the next day after the temps cooled down to 105. anything is hot after 105.
when they were building the freeway, I was changing it every 2 months beause of the gritty atmosphere.
bottom line, if you worry about any circumstance that bothers you, just kick out about $20 for oil and filter, and get handy.
remember, it's your engine and drive train, get active with your maintenance, and just know you did all you could to be a part of the well maintained.
Oil is cheap insurance, and all or most cheapo auto parts stores take your old oil because they think if you dump the oil there, you will spend money while you are there. besides, they get money for the oil they recycle.
Besides I maintain a jet, so I read a lot of the oil manufacturer's B.S. that comes out, and oil is indeed what you perceive it to be. phew!

 

Oil companies would love for you to change your oil every 3000 miles.

7500 miles is probably fine. If you want to know for sure, spend $20 and get a sample analyzed. These guys will tell you everything you want to know: http://www.blackstone-labs.com/

Dave

 

Exactly...used oil analysis is the only way to know exactly what is happening inside your engine. Do a google search for "Bob is the oil guy" - everything you ever wanted to know about oils, and some things you probably didn't!

 

Class action lawyers love it if you don't.

http://www.oilgelsettlement.com/

Chrysler has a similar complaint going on. The proximate cause of these problems is not changing the oil often enough. My owners manual says you can change the oil at 7500 miles too...normal use. Normal use meaning long trips, limited stop and go driving, ect. Most people fall under the severe use catagory which is the standard 3 month 3k mile interval. jmo

 

I change mine every 5-6k miles and I have a volvo over 250k miles and the vette just passed 160k, never had a problem. But, the 3k mile change was started by Jiffy lube and othe type companies. Until they came along, most people changed there's about 7-8k miles(what I was taught, so I chalk the 3k mile changes upto could advertising and taking advantage of peoples fears.

The best oil out there, is the one you like. They are all pretty equal, none that are reasonably priced are better than any other. Royal purple and amsoil are good, but are priced to high for DD.

 

Common Randy. You're old enough to know better than that. That sounds like something a 20 year old would say. I don't think Jiffy Lube type places even existed before the 80's. I know there wasn't such a place in my area before then or latter.

I used to have a link to an article in popular mechanics on the subject. Unfortunately I can't find it now. The gist of it was oil change intervals have been debated and adjusted all along. Before the advent of detergent and multi viscosity motor oils, the recommended oil change could have been as low as 600 miles per manufacturers recommendation. Jiffy lube wasn't even an idea in anyones head at that point. 3 months 3000k miles has been pretty standard at least since the 70's for 'severe use' which most people fall under. It's pretty standard because it's a reasonable amount of time and distance and is considered safe for everyone. I would agree that it's overkill for many, however there is some logic to the 'oil is cheeper than engines' line of thinking. Having been a mechanic in the past, and having seen engines coated with sludge...my wifes '72 pontiac when we got married included, I can say without a doubt the cause was extending the oil change interval to far. Contributing factors in my experience were the engine never getting up to operating temperature either due to a defective thermostat or the car only used for very short trips. The old lady with the 20 year old car with 10k miles, driven once per week to church type of situation. I'm sure following the 3 month 3k mile interval would have prevented sludge in the engines that had it 100% of the time. I'm sure the same is true today. The thing to remember about oil whether it be regular or synthetic, it doesn't wear out. It becomes contaminated by blow by, metals wearing off the bearings, cylinder walls, cams, moisture, ect. I've known a couple of guys over the years that never changed oil. They just added it. I don't recall them ever having a problem either. I don't think I'd recommend it to anyone though.

 

I change mine every 3,000 miles.If you not afraid to drive your lovely Corvette 7,500 on the same oil then I can save you some money. You can have my used stuff and the filter for free.

 

That must be some oil, 3,000,000 miles on one oil change .

 

Must have a really good filter. Do what your GM manual says and you'll be fine. 3 months 3000 miles is OCD territory.

 

Here's an article (quoted with permission by AMSOIL) from Lube's N Greases editor David McFall that discusses the topic and mentions Jiffy Lube's (owned by Pennzoil) 3 mo/3k mile ad blitz a few times. I don't think Randy's that far off the mark.
Motor Drain Intervals: How Long Must We Wait?

AMSOIL Performance Tests

 

buddy, you drive a vette! if u drove a honda id say ya go 5 or 6 thousand, but its a vette for gods sake, treat it like it deserves to be treated, or might get mad and blow a rod through your hood just to show whos boss,

 

I used to change every 3000 miles, everything that I have read in recent years has said, that with Mobil 1, the only thing that you are saving by changing the oil sooner is the oil company's profits. Very few engines die because of wear caused by oil changed within the manufacturers recommendations.....

 

The 3 month, 3k mileage recommendation comes from the 60s when both oils and engine components were much rougher from the factory. That was the recommendation for my 67 Camaro. Everyone is entitled to his opinion on how to spend his money, but to me, using 60s service intervals on 80s and later vehicles, is like trying to buy the earlier grade and lessor quality oils just to do it the way dad did.


http://neptune.spacebears.com/cars/s.../oil-life.html

For what it is worth, these guys conducted a pretty rigorous test over a 2-1/2 year period with Mobil1 and Amsoil in an LS1. While not scientific to within 1%, they did do an oil analysis every 1000 miles and did keep very good notes. Using Mobil 1, they were able to go 18,000 miles with one filter change and some added oil to make up for the analysis sample losses and the filter change. The 18k is an extreme example, but they have shown to me that Mobil1 can easily go 7500 ~ 10k miles or 1 year. Every year in the fall I replace the filter and Mobil1 in my Vette. Your mileage may vary.