Out of personal experience for you guys, do fuel additives really work? Allow me to elaborate: I recently bought Marvel Mystery Oil, Lucas Upper Cylinder Lubricant, and STP Fuel Injector and Carburetor Treatment and I added Seafoam not too long ago; These are claims as to what the products supposedly do:


The Marvel Mystery Oil - Boasts that it helps to 1) Extend engine life, 2) Improve Fuel Economy 3) "Cleans the engine from inside out" 4) "When added to engine oil, Marvel breaks down and removes harmful deposits of sludge and carbon. Clean engines run better and longer!"

STP Fuel Injector and Carburetor Treatment - Claims to 1) Fight deposit buildup and engine friction, 2) Maintain optimum engine efficiency, 3) Fight friction on piston rings/cylinder walls, and 4) Save gas by keeping injectors and carburetors clean

Lucas Upper Cylinder Lubricant and Injector cleaner - 1) Eliminates need for higher octane fuel, 2) Restores lost power, loss of fuel economy, burned pistons, and avoids premature overhauls due to fouled injectors, 3) Lubricates rings for longer cylinder life, 4) Cleans and lubricates carburetors, Injectors, and valve seats, 5) Eliminates carbon in the cylinder which causes pre-ignition, loss of power, burned valves, and broken rings

Seafoam - More or less all of the above (I don't have the bottle with me)


Now, do these products really clear out carbon buildup, and eliminate sludge in the combustion chambers, all while cleaning my carburetor(s) and injectors, curing pre-ignition, and restoring lost power and fuel economy? What about those Gas Treatments that express how well they improve your gas mileage? Now, as well all know a few of these products have actually been proven to work, while most others are just a scam on those suckers born every minute. The Marvels Mystery Oil I have heard gear heads have been using for decades, as well as seafoam because they "work", but do they really do those aforementioned things in your experiences?

 

I'm not big on oil additives, most don't live up to there claims and some can actually harm the motor. I know Caterpillar will not honor a warranty if some, like Lucas Upper Cylinder Lube, have been used. Some will increase the viscosity of your oil and can clog smaller oil passages.
That being said, I do like Seafoam. But then it is more of a cleaner than a lubricant. I can't remember if it says on the label but was always told to change the oil about 500 miles after using it.

 

I've had limited luck with Seafoam on motorcycles, but I've never had it do much on a car/truck. The rest of 'em don't seem to do much of anything worthwhile, to me.

That Marvel Mystery Oil gave me better compression and less piston slap on a clapped out old Duster that had shot rings and bulged out cylinders, but got the same effect by just using thicker oil.

 

I figure my truck was designed and engineered to be filled with a seasonally appropriate multi viscosity engine oil.
I follow recommended change intervals and don't overheat it or run it too cold.

MMO and Seafoam can help un-stick gummed up rings
Why should I be guessing what it needs.

 

I've used Seafoam transmission cleaner and it worked well. Have tried Seafoam through the carb to clean up valves and carbon, but it didn't seem to help the valves - turned out they were burned, not sticking.

 

Go look up the MSDS info on those products and you can maybe formulate your own for lots cheaper than the $65/gallon they cost at the parts store.

For example, Sea Foam is basically mineral oil, isopropyl alcohol, and naptha (a solvent, e.g. mineral spirits or paint thinner or lighter fluid).

Sea Foam | MSDS Downloads

 

Most of those are decent products. I think the sea foam will clean up carbon deposits if you use it right. I was told to put a piece of vacuum line in the can and hook the other end up to a carb vacuum port. Let it run and suck some sea foam in it. Then kill it for a few hrs. Do a start up and drive it on the hwy wide open to blow out the carbon.

The other stuff shouldnt be used (IMHO) unless your motor is going South. The oil additives will give you a little better oil pressure if your bearings are going bad.

If your carb is dirty then pull it off and go through it. Mechanic in a bottle cant do the job of a carb cleaning or rebuilding.

IOW I would have to be having some bad issues before I would be looking for one of those products to help me out.

 

I'm not big on additives either, but I do trust Marvel Mystery Oil. That stuff has been around since World War II, and it smells nice. I had a "tick" in my engine for about a year after it sat unused for a while, and an old timer mechanic told me to get a bottle of Marvel Mystery Oil and add it to the engine oil. And it worked! When I changed the oil that was treated, it was blacker than I had ever seen it before. The tick is gone, and that was 5 years ago and it never came back! I still use it from time to time as a fuel stabilizer, and add a pint or so right before an oil change.

 

That reminded me, my brother had a similar experience. He bought a vehicle that sat on a used-car lot for quite some time and had a lifter tick that wouldn't go away, even after several changes of oil. He finally used something like MMO and the tick went away - but in his case he had to continue to use a can of MMO in each oil change or the tick would come back. Perhaps a different viscosity oil would have fixed it, but he went with what worked - for years.

 

I do like Lucas gear oil additives for standard trannies and rear ends. I use a little im my clutch reduction gear drives on my mortar mixers.

 

I thought this thread was about "Fuel Engine Oil Additives"
I'm not really understanding all the discussion about Seafoaming of combustion chamber deposits and augmenting gearbox or rear end lubricants.

 

For the fuel injected cars, I have found Redline fuel injector cleaner works well.

I use STP oil treatment regularly in my 82. She burns and leaks oil, so to help prolong the life before the eventual rebuild....

I add 2 stroke oil to the diesel in the 2000 Powerstroke. Helps lubricate the injectors. When I don't use it the injectors clatter.

I Seafoamed a Jeep Cherokee and the smoke from the exhaust was enough to bug fog the entire neighborhood. Jeep ran better after....

Never tried MMO, but have put ATF in the engine oil to clean a motor out.

 

Years ago, a graphite/zinc additive for engine oil was around. I heard old timers talking about how it will lube(to a point) the bearings if you loose oil pressure.


Is that still around?

 

I have heard that if you run transmissions fluid through a carburetor before you remove it, then you would not have to go through it later. That's because it keeps everything lubed and seals and gaskets good in the carburetor. I have also heard that running the marvel mystery oil through your carburetor will loosen those noisy lifters. And as for Lucas engine oil additive, that's stuff is as thick as crap. It helps with those worn out valve stem seals and etc. Just my two cents.

 

I need to start running some tranny fluid in my diesel fuel again. I didnt do it after the rebuild so it would help to seat the rings as well as everything else. Now that is done so I need to give the injectors a little help.