Fuel Additives - Do you see value in them?

[RVAWagon]

So it's been a while since there was a fuel additive post, it looks like the last one was commented on back in 2014.

I'm just curious if anyone here runs anything through their tanks regularly, either a few times a year or each fill up.

I've got a stock '87 GW with 137K on it and it's my daily driver. I do about 100 miles a week and I run Lucas Upper Cylinder & Fuel Injection Cleaner at each fill up and it seems to do a good job. It says that it works to clean up carburetors as well, but I'm just curious if anyone has anything else they like.

[ShagWagon]

I

[ShagWagon]

Illl throw some marvel mystery oil in every now and then to my fuel and oil to break up anything..

[MysticRob]

I've seen a lot of youtube vids and read articles that the stuff works decently but isn't a cure-all. I used to pour Seafoam type products slowly down the carb for my early 80's Mustang, but later just used water, which worked just as well without all the smoke killing the neighborhood critters.

Seafoam in the crank case is something I still do to remove any sludge.

You can actually make your own Seafoam type cleaners much cheaper using any number of readily available chemicals.

[joe]

I use Seafoam or other fuel system cleaner in pretty much all my cars/truck/bikes a couple times a year in a tank of fuel as a preventative maint drill. It's NOT a magic tune-up in a can/carb rebuild so won't clean an already gummed-up/dirty system but does seem to keep them cleaner longer. Results are most noticeable on my carbed bikes.

[rang-a-stang]

In my fuel injected cars, I run a bottle of Techron fuel injector cleaner through them every other oil change. I have never read a bad thing about it and it's pretty cheap at Costco. My Mazda with direct injection has 130k miles and still idles as smoothly as it did when it was new even though it does not have a fuel filter. I assume that is partly because I have clean injectors from the Techron. There are different versions of the Techron line and the injector cleaner is the good one. The fuel system cleaner does not seem to be as effective (so I've read). My Cherokee gets nothing added to the gas. It's cheaper/easier to rebuild a carb (or now a TBI) than run fuel cleaner through it every so often.

I am not a fan of Sea Foam myself. My Mazda gets gnarly buildup on the intake valves and it has to be mechanically cleaned off. To do that I have to remove the the intake, soak the valves in solvent, blast them with walnut shells, then put it all back together. I do it about every 45k miles. The first time I did it, I soaked one cylinder's valves in Sea Foam, one in mineral spirits, one in denatured alcohol, and the last one I sprayed with some generic purple oil cleaner stuff. The Sea Foam did not soften the goop on my valves anymore than any of the other solvents and was by far the most expensive. The best cleaner was the generic oil cleaner.

I also had a buddy with an RX7 and when he did his rebuild, he did a similiar test on the face of his rotors. He said the carbon build up on the face of his rotor laughed at Sea Foam. I don't remember all the different cleaners he used but he said the best cleaner was EasyOff. I wouldn't spray easy off down my engine though...

[RVAWagon]

All good info

[MysticRob]

I am not a fan of Sea Foam myself. My Mazda gets gnarly buildup on the intake valves and it has to be mechanically cleaned off. To do that I have to remove the the intake, soak the valves in solvent, blast them with walnut shells, then put it all back together. I do it about every 45k miles. The first time I did it, I soaked one cylinder's valves in Sea Foam, one in mineral spirits, one in denatured alcohol, and the last one I sprayed with some generic purple oil cleaner stuff. The Sea Foam did not soften the goop on my valves anymore than any of the other solvents and was by far the most expensive. The best cleaner was the generic oil cleaner.

I also had a buddy with an RX7 and when he did his rebuild, he did a similiar test on the face of his rotors. He said the carbon build up on the face of his rotor laughed at Sea Foam. I don't remember all the different cleaners he used but he said the best cleaner was EasyOff. I wouldn't spray easy off down my engine though...

Yeah, I didn't see a point of of using it any longer on or in combustion surface areas based on everything I'd read and seen. Carbon deposits and stuff like that seemed to be far too resistant to Seafoam and other cleaners like it, but I did my own experiments with crank case sludge and those wetter deposits that it's able to break down easier, and I came away impressed enough to still dump it down the crank case.

I'd heard Berryman's was good stuff, but have no experience with it. Nor do I really have any experience with using it in the fuel tank, though I've read those chemicals are good for dissolving the presence of water and things that clog carbs up.

[nograin]

No.

[chubbinius]

If my 70 is going to sit for a bit I add some StarTron enzyme fuel treatment to it to counter the ethanol. I also put a little MMO in the tank on all my vehicles every four tanks of gas and every other oil change.

[FSJunkie]

Modern fuel is very different from the fuel these engines were designed to effectively burn.

Modern fuel contains a lot more detergent additives and cleaning solvents than old fuel did to combat deposit formation because the new GDI engines are so prone to deposits. Those extra cleaning additives do several things. One, they reduce how much of the fuel is actually "gasoline" that engines are supposed to burn. Two, it removes some of the lubricating quality of the fuel, or "lubricity". Ethanol is also a cleaning solvent that reduces lubricity. All this means that compared to fuel of olden times, modern fuel is better at cleaning but worse at lubricating.

I sometimes use Lucas top cylinder lubricant. It adds some lubricity back to the fuel that can reduce valve and piston ring wear while helping them seal better. All my engines feel like they run a little better with it. Marvel Mystery Oil gives similar results.

[Ristow]

good test on fuel lubricity. both in information and content. anyone using Lucas for it "upper cylinder lubricant" needs to have a look. especially in a diesel application.

https://jatonkam35s.com/DeuceTechnicalManuals/Diesel_fuel_additive_test.pdf

lubricity is fairly important in diesels for injector life. current fuel is not optimal for injectors so additives are common.



for a gas engine,i don't use anything. as stated above gas has enough cleansers in it from the pump.

[letank]

Impressive test from the diesel folks, dated 2007, any updates from 13 years ago?


I never used too much of anything... may be techron once in a while because it was inexpensive at Costcx



Seafoam is basically diesel gas and alcohol, so sure it will smoke on a gas engine...

[Ristow]

That is the most non biased and scientific one I have found. I like Lucas stuff. But the upper cylinder lubricant claim on that one looks to fall flat. It does appear to be a great cleaner tho, guys on the truck forums have reported great fuel system cleanings with it.

[FSJunkie]

BG Products are the best on the market if you can get them. I toured their factory once.