1) It seems that there is mixed opinion. Most people seems to think 3-4k is fine. One person said synthetic might go for 5k.
Acturally I suggest the manufacturers recommendations and I beleive they are all recommending more than 5K for normal conditions.
Are you aware that some test are showing that at least some modern oils are showing better protection over 5,000 than in the first 500. From what I have seen the difference is very small and both are providing lots of protection.
I would suggest that we don’t find many, if any engiens today experiencing failure due to following the manufacturer’s recommendations, rather those that show problems are the result of thing like oil leaks failure to change it at all etc.
I think you can easily do 10K on synthetic, but your warranty will require otherwise. Personally, I’ve been using synthetic since Mobil 1 came out in 1976 and never gone less than 10k. Normally, I’ll do 15k. Never had a hint of a problem. ymmv!
First, the mechanic makes more money when you change the oil more often. Even if you changed your oil once a month it would come out black. Second, [i][u]DO NOT drive your car with sludge remover in the engine.[/i][/u] If you read the directions on the sludge remover container, it says not to drive the car with it in the engine. You put it in the engine and idle the car for five or ten minutes and do your oil change. If you really need sludge remover, make sure you read and follow the directions carefully, but I don’t see any reason for you to need it if you have been changing your synthetic oil every 5,000 miles. Based on what you have told us, keep doing what you have been (oil change with synthetic every 5,000 miles), and find a new mechanic.
As stated before, oils are considerably better than 20 years ago. I attend a conference every year where oil company engineers present detailed updates in lubricants. The base stock, that’s the oil before the additives are put in is now considerably better as well; the viscosity range is very predictable now, whereas 20 years ago, amany oils were not in spec. when tested.
Engines last longer now partly beacause oils are better. The additives package has been improved and increased; oil is now about 25% additives. So, don’t let anybody tell you oils have not improved!
In order to sell more cars, the manufacturers have really stretched the oil change interval, resulting in owners almost forgetting about changing the oil, because all the other maintenance has almost disappeared. As a result we still have too many unnecessary engine failures, but dilligent owners now get 400,000 miles out of an engine without an overhaul!
These dilligent owners know when they have “severe service”, and should change oil more often, and when they can stretch the interval without getting to the “additive depletion” stage of the oil. Many poster shoot from the hip without addressing the type of driving which really determines the interval.
With modern engines with fuel injection and very reliable ignition, a normal dino oil will easily last 3000-4000 miles even in stop & go and cold weather driving. But constant highway driving at legal speeds can stretch that to 5000-6000 miles. Synthetic oil can stretch it further, but all oils are limited by the additives in them. Mobil 1 now has an “extended drain” synthetic; it has more additives, and is good for over 10,000 miles of highway driving. I would still change it out at 7000 miles in stop & go driving.
C’mon you guys, sciconf is looking for a simple answer. Here goes, sciconf, look at your owner or maintenance manual. Using synthetic oil you will be fine if you use the intervals there for regular or severe service what ever applies to your situation.
Agree; that will cover 99%+ of the situations one might encounter and will give maximum engine life. The key here is to use the right viscosity for the weather encountered.
Oil has changed considerably in the past 20 years, but definitely not as much as it had in the 20 years before that.
If anyone truly wants to know what their oil change interval should be, do this:
Go to http://www.blackstone-labs.com/free_test_kit.html and have a free oil analysis kit sent to you.
When you get the kit, fill the plastic bottle with 4 ounces of your engine oil, and send it back to Blackstone Labs.
Make sure you have them include a TBN analysis for an extra $10.
They will then tell you how much longer you can go on your oil.
For a total of $32.50, you can find out first hand that you can most likely go much further than 3k miles on your conventional oil, and considerably further on good quality synthetic oil.
But its up to all of you to do whatever you want with your cars.
I change my oil every 5k miles, pay my $24, and get it and the oil filter changed at the Firestone Dealer up the block from my house. Right before I have the oil changed, I pull out another oil sample, and send it to BlackStone Labs, just so I know how the engine is holding up to my driving style.
I change my oil every 5000 to 6000 miles with just regular oil ,< WHATS EVER ON SALE> and i have over 200k on my 2 cars and almost 300k on 1 truck and never a had oil related problem .I must be doing something right.So you should be ok at changing oil every 5000 miles…