I have always filled my Outlander where I can save, usually Costco or Meijer, whichever is nearest when the low fuel alarm go off. But looking at the prices of Shell and BP Amoco makes you wonder if it's worth the few extra $ to spend and get their gas, which they advertise as having additives to fight deposit build-up in the engine fuel injection system. I am strongly considering just adding STP fuel additives, but I'd like to hear opinions about its use, and if there are long term negative effects on the engine, or emission sensors. Mitsubishi recommends fuel with additives (detergents) to maintain good engine condition, but will this be the same as using 3rd party fuel additives such as STP?

 

Not a bad idea, but Ill tell you this: Zmax or whatever killed my Monte Carlo.

 

I used them for years, but there's one good way to clean out injectors...extended interstate runs. If you don't do a lot or just enough of them, the additives work fine and aren't supposed to hurt anything.
I've even used that Outlaw brand after a month of no interstate runs and it's always made my engine purrr after a good highway run.

Anyway, to answer your question...IMO, it's worth using the "good" gas because if you think about it, you have a full tank of "cleaner" in your tank instead of a tiny bottle's worth. If you don't feel like spending the cash on it every fill up, do it every 3rd. It takes awhile to get build up in the fuel system unless you use crappy gas all the time.
Military base gas is crap btw. I fill up with base gas and the exhaust tone gurgles and coughs. When it's time to fill up again, I use Chevron, Shell, or any other "good" station and my car purrs, lol. Seriously.

 

fuel additives are a COMPLETE waste of money. Do NOT ever bother wasting your cash.

everything your car needs is already in the fuel you buy.

 

I'm a strong believer in differences in fuel quality between gas distributors... I would avoid filling up at the independent gas stations, 'coz you never know if they can be trusted.

I swear by Shell "economy formula" which is also one of the cheapest over here (although in Belgium there is no such thing as fuel being cheap), and now and then I use JET (ConocoPhilips) to clean the injectors since their "95+" RON is claimed to contain multifunctional additives that clean the engine.
It appears to me that the fuel of JET produces a bit more noise and gives less performance, I also noted a small rise in fuel usage... that may be caused by the additives they use?

regards

 

when shell or bp or any of those gas stations say thier gas has more additives they are only talking about the premium fuel not any of the lower grades....and all of the lower 87 octane gas is the same from what ive heard the only gas that is exclusive to manufacturers is the brands premium gas EG: the joes manufacturing plant makes 90 million gallons of 87 gas trucks from all of the companies use that gas to deliver to the station so shell trucks pb hess chevron as well as all the other guys go to the same place to get their gas.........thats what ive seen on the discovery chanel networks the only thing different is when it comes to 93+ octane then it gets more exclusive

 

I like to use Shell when I can. They're the only 'Top Tier' gas sold in my area. Top Tier is astandard setup by a few automakers..GM, BMW, Honda, Toyota, VW/Audi and has more detergents than minimum requirements set by the EPA.Check out www.toptiergas.com

Around me, Shell is about the same price..usually within a few cents a gallon, plus I have their Mastercard, which gives me a 5% rebate on their gas and 1% of other purchases toward gas purchases

One of the few additives worth getting is Chevron Techron, butusing a qualityformulationfrom a station that goes through alot of gas (gas can go bad) is your best bet

 

Shell is Top Tier, and a requirement to be top tier is that all grades have to meet the standard, however the premium grade could have even more detergents.

The base gasoline is the same for all stations, however, when it is pumped into the tankers..different additive packages are added based on the brand. Shell gets the Shell additive package, BP gets their own package, Chevron gets theirs.......butthe no name brands probably get the same EPA minimum package

 

All i have to say is just use the grade that your owners manual tells you... and thats all. Screw additives they suck