This lawnmower never needs an oil change
 

(from my blog, PVcharts.com)

Briggs & Stratton has come out with a cool new lawn mower that never needs oil changes! According to their website, the secret is a better air filter and a cooler-running engine, which extends oil life. The owner just needs to check and top off the oil occassionally.

http://www.pvcharts.com/Eblog/wp-con...ne-300x300.jpg

The other feature of this system which isn’t mentioned in the PR, I’m sure, is that lawnmower engines tend to burn a fair amount of oil. Thus they will frequently need topping off, which replenishes the oil’s additive package. The company would rather not focus on oil burning as a feature, but I would bet it is crucial.

As electric vehicles become much cheaper, conventional gas engines will need to exploit all kinds of technology to stay competitive. And let’s face it, oil changes are one of the worst aspects of a gas burner. So, my humble prediction is that automakers will advertise longer and longer oil change intervals. We may even see some creative systems where oil is no longer drained, ever, but partially siphoned out and topped off to replenish additives.

There is precedence for this “replenishment” technique already. A couple links from people who NEVER changed their oil follow– they just topped off as old oil was slowly burned off. If you’re “lucky” enough to have a car which burns oil (mine doesn’t), you could probably pull this off. My father’s 1996 diesel F-250 went about 50,000 without an oil change and was still ticking fine at 180,000 miles.

There are at least two synthetic oils on the market (Amsoil Signature and Mobil1 Extended Performance) which guarantee suitability for 15,000 mile oil changes. So, it isn’t a huge mental leap to imagine an oil-change-free future. I would never change mine at less than 5,000 miles. If you do, you’re wasting cash.

122,000 miles without an oil change – Nissan truck

38,000 miles without an oil change – VW Jetta

250,000 miles – ’72 Buick Rivera – discusses Car Talk and a government study as well

13,000 miles – Honda Insight

I have a Subaru that never needs an oil change either - just add a quart every thousand miles, change the filter every three. The old oil leaves via assorted small convenient exits.

Yep, that's what I'm talking about. Now somebody just needs to design a system that constantly siphons off old oil (burn it or store it) and feeds in new oil from a reservoir.

Sounds like a 2 stroke to me.

My mom's old Aztek never needed an oil change either...it all got burnt before I could get around to it :p

That has been around since at least the 1950s on diesel engines. Detroit diesel used a needle valve to meter engine oil into the fuel to burn it off. Then the operator would add more.
By the 1960s they had auto oil fillers installed on engines.

I would still change the oil.
It's likely only about 3/4 of a quart.

Oil is cheap. Engines and vehicles are expensive.

Cool. Now integrate it with software so the car knows how much to burn off (or store) and give the driver an indicator to add more on the dashboard. It sounds like any patents on this stuff should have expired by now.

This is news? I've had one for a good many years. Not only does it not need oil changes, I never have to put gas in it, either. Or pull on a rope dozens of times, hoping that this time it'll start. Or listen to the noise of an inadequately muffled IC engine. No, I can just flip the switch and go. Plug it in to the charger occasionally, sharpen the blade once a year, and that's it.