GSteg

iTrader: (15)

My car has always ran Chevron 91 octane since it rolled off the dealer's lot. I pulled my injectors out at 140k miles and bench test them to find out they were slightly clogged. I set the fuel pressure to 51 psi for the cleaning process and after running the cleaner through the injectors, the pressure dropped to 48 psi. That's 3psi of loss pressure due to clogging, which translated to an increase of 2-3 mpg on the highway for me. Having a thin film of byproduct in the exhaust pipe won't do anything because the exhaust pipe is much larger. On the other hand, the injector's spray tip is very small. Over a lifetime, most drivers will not notice anything because the changes are so gradual.


If these things are considered 'feel good' items, then so are synthetic motor oil because they do nothing to the measurable performance/fuel economy It's only a 'fuel good' factor if you are buying random cleaners and expecting them to be effective. Not all cleaners are the same.

IS-SV

Sounds valid to me, or specifically an accurate report on 1 isolated case of 1 specific car. By all means that car needs more regular use of approved cleaner, and in that case it goes beyond "feeling good", agreed. And probably a good suggestion for the few that keep cars for more than the average number of years, thanks.

Keep in mind my original post which mentions "lifetime", my ownership experiences don't involve keeping cars for over 10 years and for over 100K miles, so not applicable.

GSteg

iTrader: (15)

The problem is most people think injectors either work or they don't (fully clogged). There is a difference between fully clogged and not running at optimal performance and most cars follow the latter. I've tested enough injectors to know 'quality' gas only helps reduce the amount of buildup, but it will not eliminate it because nothing is ever 100% clean in an internal combustion chamber. Over time, you WILL have buildups.

IS-SV

^^ Good clarification, all part of the automotive (engine) aging process.

RXGS

iTrader: (2)

I sometimes use marvel mystery oil in a tank of gas since the fuel injectors on my es300, and most of these 3.0 toyota/lexus v6's are so loud, and there is a difference in the noise level. Gas mileage also does slightly increase, but then again it's not a new car.

bitkahuna

iTrader: (20)

where is the evidence for this? for example, actual tests comparing engines driven with and without cleaners?

bitkahuna

iTrader: (20)

crickets.

T0ked

iTrader: (2)

I don't know if it works or not but I use a bottle of gumout regane once a year in each car as psychological reassurance. Seems to be working well on my psyche.

IS-SV

"gumout regane", does that promote hair growth like Rogaine, or is it mostly placebo effect?...jk

GSteg

iTrader: (15)

Sorry been busy for the last two days.

You can't really compare engine to engine because unless the injectors are ridiculously clogged, then you probably won't notice a difference in acceleration. Most cars fall under this category. In some older GM vehicles, injectors clogging was not uncommon at all, and the remedy was to use GM's fuel injector cleaner (great stuff). That did the trick for a while until it started clogging up again. I use them to maintain a good flowing injector. I went with Chevron 91 octane thinking it was all fine and dandy only to find my injectors reducing fuel pressure.

Most people won't care to use cleaners, then again most people don't ever change the coolant and brake fluid either.

GSteg

iTrader: (15)

Gumout Regane is definitely on the good list. It contains a sufficient amount of PEA (30%?) and it's not too expensive either. All the other Gumout (non-Regane) are not worth paying for.