fuel additives

[pearly8]

Any opinions on adding fuel system cleaners or injector cleaners to fuel as a maintenance item?

My Dad used to swear by pyroil, but that was long ago with carbs.

[MikeHalloran]

Long ago, when EFI was new, injectors tended to accumulate 'varnish', which interfered with atomization, and, e.g. made a FI car run like a carbureted car with plugged transition jets.

Varnish accumulates in typical commuter drive cycles, which were not simulated during EFI development, where the engines were run continuously, not parked and hot-soaked. Recent injectors are varnish- tolerant, and the fuel has changed some, too.g

My 85 Camaro V6 ran like it needed a valve job when the injectors got varnished up.
The only thing that was effective against the varnish was Marvel Mystery Oil, added to the fuel at 4 fl. oz. per 12 gallon fillup. It usually made an amazing and amazingly rapid change in the car's drivability, within ten miles or less.

In the five Camaros I've owned since then, MMO made a less spectacular difference, and wasn't needed on a regular basis. But if you have a EFI car or a carbureted car that's feeling a little funky, MMO is still the cheapest thing to try first.

[dom]

Only thing I ever add to a tank is dry gas when I don't intend on driving, or using the machine much.

[Eric]

Any opinions on adding fuel system cleaners or injector cleaners to fuel as a maintenance item?

My Dad used to swear by pyroil, but that was long ago with carbs.

If you use name-brand gas that's not "aged" (avoid low-traffic stations; buy gas from stations that are always busy - this means fresh fuel) you should not need additives. The additive package in the gas you buy (octane grade is not relevant here) should be sufficient to keep everything right.

More important than additives is regularly changing out the fuel filter. I do this once a year. Also, try to keep your tank at least half full (ideally 3/4 full) most of the time, which will help avoid sucking up the particles/debris that settle at the bottom of the tank. Ever open up an old fuel tank? It's sometimes quite a sight!

[dom]

Excellent advice Eric. Not even to mention keeping your tank at least half full keeps that fuel pump nice and cool too. An electric pump that is always cool will have a long happy life!

[grouch]

The only additive I ever use is Stabil for my generator and back up fuel cans. It will keep gasoline fresh for a year or so. Sour fuel can really cause problems.

[dieseleverything]

I use Power Service, but I have a bunch of diesels.

[ChevyMan]

If you use name-brand gas that's not "aged" (avoid low-traffic stations; buy gas from stations that are always busy - this means fresh fuel) you should not need additives. The additive package in the gas you buy (octane grade is not relevant here) should be sufficient to keep everything right.

More important than additives is regularly changing out the fuel filter. I do this once a year. Also, try to keep your tank at least half full (ideally 3/4 full) most of the time, which will help avoid sucking up the particles/debris that settle at the bottom of the tank. Ever open up an old fuel tank? It's sometimes quite a sight!

"Also, try to keep your tank at least half full (ideally 3/4 full) most of the time, which will help avoid sucking up the particles...." is a good idea. In the same vein, it's just as wise NOT to gas up, if possible, whenever the delivery tanker is filling up the storage tanks. You can imagine how much "particles" will be moving around when the tanks are being filled, you know what I mean?

Larry

[Eric]

"Also, try to keep your tank at least half full (ideally 3/4 full) most of the time, which will help avoid sucking up the particles...." is a good idea. In the same vein, it's just as wise NOT to gas up, if possible, whenever the delivery tanker is filling up the storage tanks. You can imagine how much "particles" will be moving around when the tanks are being filled, you know what I mean?

Larry

Yep!

This is also why I change out my fuel filters every year. It may be more often than specified, but a filter is cheap and easy to replace. Fuel system problems are often neither!