Since I bought my 2001 Outback Limited in December, it's been working great
and I have been doing many precautionary things to ensure it continues to
work great. One of these is considering using fuel injector cleaner. Being
that I don't know the previous owner and if they used any of this, does it
hurt whatsoever to use Gumouts Fuel Injector cleaner on a Subaru?
Also I noticed Gumout suggests using their fuel injector cleaner every 3000
miles where as STP suggested using their fuel injector cleaner once every 6
months. Whats the difference for this? Does fuel injector cleaner *really*
clean off the intake valves, improve the delivery of fuel to the chamber,
I most often use fuel injector cleaner in response to an engine being a
little "ragged." It's most noticeable at low engine speeds and especially
with manual trannies. The clutch seems to get real touchy, not the rhythmic
judder of a grabbing clutch but rather pulling the engine speed down a lot
and needing to feather the clutch to take off. It also can clean out the
check valve that holds pressure in the fuel rail, so the car starts on the
first crank instead of the second... but it isn't a cure-all.
My take on it is that it is a cheap thing to try that can't hurt, might
help, and is more valuable if you use cheap gas (like I do). A couple or
three times a year is enough. The better brands, like Chevron and Shell,
have enough detergents to do the job. And some cars don't care about cheap
I've tried RXP in the past. It seems to do a great job of decarbonizing
the combustion chamber and surrounding areas (valves, tops of pistons
and such) but I don't think it's so much of a fuel system cleaner as
Techron and others. I could be wrong.
I won't dispute that. They kinda promote it as a do-all additive.
Normally, I think mechanic-in-a-can remedies are a waste. Techron and a
coupla others may be an exception. I think gas dryers work if there's a
little water in the gas. And I certainly would TRY some bottled stuff
before spending huge dollars on a repair - but I try to have realistic
I'm on the fence here: like the pudgy person who buys into each new
"wonder" diet, I try these things out of curiosity, wondering if MAYBE
one will perform as advertised. I think most of them probably do ONE
thing well, the rest is hype. Trick is finding which thing they do, and
which one does that job best. It keeps the mfrs in ready cash, no?
In reality, I'd say as a preventive measure, most of these things don't
hurt, but as a curative item, well, that's probably not likely!
On Sat, 01 Apr 2006 18:26:50 GMT, "Bradley Walker"
Given the fact that all gasolines now detergent additives, there is no
need to add any yourself on a regular basis. Unless you have symptoms
that lead you to believe that the injectors are dirty you can save
your money. If it makes you feel better, an occasional container of
Techron in the tank shouldn't hurt but probably won't help much
Concentrated detergents can dilute the oil, so if you're going to use
them it's best to do so right before an oil change.
My experience with Gumout years ago, when everything was carbed, was
good. I don't remember what their recommendation for was for use, but I
got my "ideas" from my grandfather, whose VW mechanic (early '60s Bug
guy, not the new stuff) suggested twice a year, or 5000 mile intervals.
Over the years, as we've gone to computerized injected systems, Gumout's
added products to their line, but none seem to be as effective as the
original to me. That could be purely subjective, though. Same w/ STP
A few years back, a parts guy suggested I try Berryman's B-12 Chemtool.
I tried it, following instructions (16 oz to 16-20 gal of gas) and it
did a LOT better job IMO. Later, I tried using 4 oz/tank w/ each tank,
and while the results don't seem as dramatic, I feel "a little all the
time is better than a lot once in a while." Recently, they came out with
a "Premium" version that's apparently concentrated a bit more (16 oz to
35 gal is the recommendation) but costs the same. I started using 2
oz/tank in one of my vehicles, and the results seem better than the 4 oz
of the "regular." Again, this could all be subjective!
Since you don't know the history of fuel system cleaning on your car,
I'd suggest you try the Berryman's in small doses so you don't "shock"
the system in case of a big buildup of goo. You can always dump in a
whole can later...
Another product that's frequently suggested is Chevron's Techron. Same
stuff they put in their gas, but you can buy it by the bottle. It's
about twice the price of the others in my area, but lots of people swear
by it, and Chevron's one of the first "Top Tier" gasoline sellers here
in the US, so I guess the auto mfrs like their product, too!
Some would suggest you put the cleaner in, run it thru a tank or so,
then replace the fuel filter. Thought is there may be lots of gum in the
tank and lines that gets dissolved and will clog the filter. It makes a
good story, but I don't know if there's any truth to it...
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