Mobil 1 synthetic oil change question....?

Question

I was told by a mechanic that suggested to me " Buy mobil 1 oil next time you do your oil change...I'll almost guarantee your high mileage engine will smooth right out, and be quiet again. and you never need to do an oil change again...because it's the best synthetic oil you can buy, guaranteed for the life of your car or xxxxxx miles, just change the filter about every three months or so, depending on how often you drive, and you'll be good to go anywhere." Does this sound like truth, or is this guy feeding me a line of bull...it's not like he was trying to sell me anything, because he only works in a garage, he doesn't own one. And he's best friends with my Father who was Certified Mechanic by trade for over 40 years. It's not that I don't wan't to believe him...but I never heard of an oil you don't have to change? Please help me with suggestion's on changing the oil of my 1990 Pontiac Sunbird with 2.0L Fuel Injected

Answer 1

Yeah, if he said you never need to change your oil, keep him away from the car...don't even let him touch your lawnmower hehe.

Mobil 1 is good oil, probably about as good as you're going to get at the typical store shelf. Royal Purple, Redline, Amsoil, etc... are premium, but not worth the investment unless you clean your cylinders with a toothbrush every month.

If you live north of the border, so to speak, it would be worth it in the cold weather to get it. Synthetic oil has a pour point much much lower in temperature than regular oil, which is important because when you start your engine (most of the wear comes from starting it up), you don't want the oil to resemble tar as it tries to get up to lubricate the engine parts.

Other than that, the advantages are there, but rather menial. One of them is that all the molecules in synthetic oil are the same size. In regular oil, despite refining, there will always be a few bigger molecules (which turn to sludge) and a few smaller (which burn off).

If you buy synthetic, be on your toes about it, because synthetic doesn't necessarily mean the man-made stuff. It used to before 1999. Mobil actually filed a lawsuit against another company (I think it was Shell - don't quote me though), because the other company was selling oil labeled synthetic, when it wasn't man-made, but it was refined very well. They ended up losing the lawsuit, and the ruling was that synthetic referred to how the oil was processed rather than the fact it came from the ground or not.

Part of the reason they got away with this is because the refining process has changed over the years. The old-school mechanic, in my experience, actually is the one advocating changing the oil every 3,000 miles like a religion. It's still a good idea, but it's not as crucial as it used to be, because that school of thought was based on the refining methods used from the 30s until about 1990, I believe. They used paraffin waxes and such to separate the crude oil out, but it wasn't perfect, by any means. It still left about a candle's worth of gunk in the oil. In the 90s, there was a hydrogen bubbling process which cut that down by about a factor of 5...and in the late 90s, that process was advanced even further, which made the differences between the well-refined organic oil (Group III oil) and the man-made stuff (Group IV) less discrete. Hence, the lawsuit.

So anyhoo, that's why 3,000 miles isn't as important as it once was...but as good as oil has gotten, you still have to change it. I personally still wouldn't push it past 6,000, less if your driving conditions are rough. There are still chemicals in gasoline, like sulphur, that will react with the oil and some of them even form corrosive materials. Also, just the heat and being squeezed through tiny clearances between the piston and sleeve, etc... break the oil's structure down.

One last thing to consider is the anti-wear additives. Part of the reason an oil can have viscocities we want, like 10w-30, is because there are long chain-like molecules which curl up small when cold, and expand when they're heated, so they prevent the oil thinning out too much. Those will break down eventually no matter what oil you have.

A lot of oil additives, which you should always avoid, have such substances in them, but it's like a cake recipe. Modern oils have them in already in the proper amounts. One example is PTFE, or polytetraflouroethylene, which they don't mention on the bottle is just teflon. Yes, it reduces friction...problem with that is, it's a solid, which clogs filters, builds up on your main bearings and whatever else. Another scam is Lucas oil additive. You'll see the little demonstration in the auto parts store where you turn the gear and it looks like it coats better, which it does, but it does so by getting air into it. At high speeds, as in the car, it froths the oil up and changes it to a light milky color while it goes through your gears, coating better, yes, but with about half the lubricating efficiency. That is why it sometimes makes the engine sound better for a while...it is coating, but at a cost...so just keep wary of that.

Answer 2

on average, synthetic oil can go about 10,000 miles. the filters can not. they can last about 5000, and that's pushing it.
Mobil 1 is good, but by far NOT the best.
It's easier to buy mobil 1 and find vs. something like royal purple, redline or even Lucas synthetic.
the advice of changing the filter every 3000 is right on, but
there's no reason to switch over to a synthetic with a 1990 car unless you live in extreme heat or cold.
you do have the change the oil. motor oil suspends the contaminents and dirt, and the filter can remove just so much.
it's an old school mechanics myth that you can leave the oil in and just change the filter.
what happens when the oil detergents break down and disappear?
change the oil every 4000 miles and the filter, use a name brand oil, you'll be fine.

Answer 3

Mobile 1 will last much longer between oil changes but even under the best if circumstances I wouldn't run any oil more than 10 thousand miles.

Also keep in mind some engines especially higher mileage ones can't handle synthetic oils, the stuff is much better at working it's way past worn seals and rings. You'll burn it like crazy. Use Castrol High Mileage designed for engines that use oil.

Answer 4

when I was traveling a lot for work I used mobil 1...and it actually increased my fuel milage as well as performance. However, you still need to change your oil...I'm thinking mobil 1 is like every 10k miles max....however you still want to change your filter every 4k miles. If you don't drive long distances over the year then I'd reccomend using castrol oil...it's good oil and is much less expensive than the mobil 1. I"ve been working on cars for many years...and never heard of not changing your oil no matter what oil is used. He may be a friend but he is misinformed on not changing the oil.

Answer 5

All I know is, a guy at work had a Chevy S-10 and he would change the filter every 3K miles and add a quart of Mobil 1 oil to replace the oil he lost with the filter change. He had over 220K miles on the engine and it still sounded new. There were no valves ticking or any other bad noises. He did say that he would change all the oil every 25K miles.

It seems to have worked for him, he is a millwright so he knows mechanical things and the lubrication of them.

Answer 6

no you still have to change to the oil in the car,just not as often,i use it and i change it around 8500 miles ,there's no oil made that will last a life time,that mechanic is wrong,every time you do an oil change also change the filter,i wouldn't go back to him,i don't think id want him working on anything i had,good luck on it.,,,PS Mobil one is a good choice,for oil i haven't has any problems from it since i been using it,good luck.

Answer 7

mobil 1 not necessary. just go with any synthetic BLEND designed for high mileage cars. ie Valvoline Maxlife