Again, this is something for TEAM Tech...

I run 89 octane through it (lowest grade that Amoco has) except for maybe every 2 months I'll put full premium in. Premium has some additives and detergents that help keep sludge fro building up in your gas tank as badly, and it actually helps clean your injectors and removes light carbon deposits from the combustion chamber.

I'm moving this to TEAM Tech as well.

 

If your running stock just use 89 & throw in a bottle of injector cleaner about every 5-6K.

 

I used to think so too, not sure if I posted it on here or not... but its actually illegal for the manufacturer not to put detergents in ALL octanes of fuel.

Don't listen to your friend, listen to Ford. 'Premium' (hate that name) should really just be called what it is... 91, 93 or 94 Ron+mon/2. The longer hydrocarbon chains of high octane fuel take longer to burn, and if you do not advance your ignition timing correspondingly, you will end up with incomplete burn which WILL leave deposits over time and "gunk" your innards. These end up forming 'hot spots' in the combustion chamber, and your car will lightly knock and consequently lose power if you go back to the correct octane fuel the factory optimized your ignition timing for.

If your engine is tuned with the compression ratio and timing with 87 octane in mind... USE THAT. There are powerful concentrated fuel system cleaners you can purchase at Pep Boys/ Walmart/ etc that you can put in once every 6 months if you are concerned.

But all octane gas by law contain detergent packages, and your vehicle was never designed to be operated on high octane fuel. The answer is NEVER (unless you get a chip or forced induction that neccessitates a change). Waste of money and detrimental to performance in the long run.

 

Ducman69 is spot on. Use a good brand name fuel of the Ford specified octane rating. I worked in the fuel industry and you get what you pay for! The big brand name fuels can be relied upon to be of consistent high quality. To be honest, if you use this type of fuel you'll never have to use any sort of fuel additive.

All the big brand names use additives that prevent corrosion, deal with water in fuel, lubricate, clean and carefully tune burning properties of the fuel...bla bla bla...

 

In the UK we use 95 octane. 98 octane used to be available but it was more expensive and offered no performance difference, I've not seen it on any of our pumps recently.

 

i used to use 89 all the time. then after about 8 months, decided to use 87, and actually noticed a few more miles per gallon. how that happened i don't know, but it worked. starting tuesday, i'm going to be using premium because of the chip install.

oh well, gotta sacrifice things here and there.

 

What if you are running nitrous? You need to run 93 octane if you do nitrous right? When you are off the bottle are you hurting your car by running 93 octane? Ive been running 93 octane for a while now. I dont want to change to lower becuase of the nitrous.

 

Tricky question... and thats the problem with nitrous cars. Unless you get a flip chip, your NA isn't at all optimized for nitrous running. Nitrous speeds up the burn rate from what I've read, so you usually want a slightly more retarded spark (depending on the shot) or higher octane fuel for a better burn. Engine knock is FAR more damaging than running too high an octane for your requirements, so that would be my first priority. Run that fuel system cleaner (not sure which ones are good)... the concentrate... once every 6 months is probably fine. That way if there is a problem with deposits building up (should take a while), you'd eliminate the issue. Mostly it just sucks because you have to pay more for higher octane you can't use/need 95% of the time off nitrous.

[ 02-09-2002: Message edited by: Ducman69 ]</p>

 

I use 87 every time, or the cheap **** as I call it.

 

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by YellowZX3:
I use 87 every time, or the cheap **** as I call it.

<hr></blockquote>
aka The Stuff our cars were engineered for. Unless you've got a chip which requires a higher octane, DON'T use ANYTHING besides 87.
Once again, use your "Search" Button for the previous threads which have addressed this. Remember the term, "Octane Junkie"...Look it up.

 

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Ducman69:
...Waste of money and detrimental to performance in the long run.<hr></blockquote>

There was an interesting article quoted here and on a local Focus board re: running premium fuel in a variety of cars from a Mustang GT, BMW, Accord, etc. sorry, can't find it, but to sum up:

The high performance cars that REQUIRED premium fuel did need it...they lost performance and mileage running on regular, BUT (Although it admittadly could have been attributed to experemental variance), the Accord, for which reg. fuel was recommended, actually LOST mileage and a bit of power when run on premium...

So as Duc said, if it doesn't call for high octane don't bother...you might be paying more to actually hinder performance and mileage too. I know, it was a Honda, but it at least shows that high octane doesn't mean more power in a car that won't make use of it...

[ 02-10-2002: Message edited by: Marction ]</p>

 

Duc was on the money...higher octane can be a detriment to a car not requiring it. The burn is
slower and leaves deposits that can hurt your performance and eventually damage you engine. I repeated this only to lead into the subject of cleaners/valve and fuel system. There are some products on the market that are too strong and will damage injectors and or hoses. Be safe use Redline or Amsoil cleaner (s) They are designed or engineered to be used as often as you wish...every fill up if you want..( a waste of your money ) without damaging other components.
If you run a quality cleaner when you change your oil that should be good. Hope this is a help.

 

87 octane and nothing but 87 octane it is then!

 

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Alkemist:
Ducman69 is spot on. Use a good brand name fuel of the Ford specified octane rating. I worked in the fuel industry and you get what you pay for! The big brand name fuels can be relied upon to be of consistent high quality. To be honest, if you use this type of fuel you'll never have to use any sort of fuel additive.

All the big brand names use additives that prevent corrosion, deal with water in fuel, lubricate, clean and carefully tune burning properties of the fuel...bla bla bla...<hr></blockquote>

That is not so true here. I can watch gas trucks all come from the same place no matter what the brand...Shell, Amoco, grocery store brand, Mobil, Speedway/Marathon Ashland....They all come from the same place...the refineries in the US are all consolidating and we will continue to see that happen. Gas is gas. It is regulated by law. Get the cheapest stuff you can. It is going to be the same!

 

Thats cool, I never knew about that. I always use 87, but when I feel my car has been good i'll buy her some 91, but I never thought about the long run effects. To think when I took my car to the track I was going to buy some of that 100 octane racing fuel. The car probably won't even run

Thanks!!

 

87 huh? well i better stop putting 91 in. thxs ive been wondering this for awhile but didnt think it was that big of a deal.

 

Well they all obviously have their own detergents and special additives on top of the regular fuel though... so at some point they are getting specialized (or its at the stations).

The stations are also critical though. The quality of the storage tank and delivery pumps can make all the difference as well. Good fuel isn't so great if you end up with sediments, moisture, and other crap in it. I also don't care what station I go to as long as it is a quality NAME BRAND station though (you can tell the difference).

 

Well they all obviously have their own detergents and special additives on top of the regular fuel though... so at some point they are getting specialized (or its at the stations).

The stations are also critical though. The quality of the storage tank and delivery pumps can make all the difference as well. Good fuel isn't so great if you end up with sediments, moisture, and other crap in it. I also don't care what station I go to as long as it is a quality NAME BRAND station though (you can tell the difference). Those no-name low-budget stations are a lot cheaper for a reason (sometimes not more than 50 feet away from a major gas station that charges more).

 

I use 92, but only because I have a Diablo installed. When I first installed the chip, I topped up the 87 that was left in the tank with 92. The car didn't run all that smooth. It got a lot better since I got a tank of pure 92.

 

Seriously...I stand behind what I say...it doesn't matter where you get it. If someone at Amoco or Mobil has new tanks or has no idea what they are doing you could have water in there so easily. That is why you NEVER go to a new gas station for a few weeks at least. I used to work at a Total station before they got bought out. I learned a thing or 2. THe guy that delivered gas to us also delivered to the Meijer grocery store and Speedways. They all have the same detergents...it is mandated. Max of 10% ethanol too.

 

Car & Driver had a very interesting article about the use of high and low octane fuels in cars that do and don't call for high octane.
Here's the link: Car & Driver: Premium or not?
Brian

 

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by b_derksen:
Car & Driver had a very interesting article about the use of high and low octane fuels in cars that do and don't call for high octane.
Here's the link: Car & Driver: Premium or not?
Brian<hr></blockquote>

that would be the article to which I was referring in my earlier post in this thread, thanks!

 

I used to work for Exxon / Esso as a research chemist and I can tell you that they most definitely use their own special blend of additives denoted by their ECA numbers (Exxon Chemical Additive). Exxon where quite happy to supply these additives / additive packages to other fuel manufacturers but only gave their ECA numbers not the chemical formulation. Other manufacturers may not use all of the additives or the additives blended in the same way. If it says Exxon (or what ever) on the pump it is. If it is non descript you have no idea what quality fuel you're getting. The only SURE fire way of getting good fuel is to go for the big brand names that have a lot to lose by supplying rubbish. Some of the others might be equally as good but unless you are completely sure you should not rely upon it. If you pay less then you will find that the additive package is not the same as a more expensive fuel. Just because the fuel is coming from the same refinery does not mean the package is the same. In the old days your engine could completely seize if you used low quality fuel, it's not like that anymore. Today you're more than likely only to see performance drop and longer term problems rather than anything catastrophic.

As for fuel additives that clean the engine etc, forget it, on a modern well looked after engine, the only difference they make is in your head! Additives that boost performance by adding oxidising agents etc (like NO but not as good) work. Try nitromethane in your fuel mix!!! Some of the additives you slosh in are 95% methanol with the other 5% all sorts of exotic crap that does jack sh**. Save your cash and stick with lower octane fast burning fuel. Higher octane is for pulling caravans.!!! Honestly, stick with good quality fuel with the octane rating advised by the manufacturer, it's been designed for it.

 

If you're using a Diablo Chip:

http://www.teamfocaljet.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=12&t=001230

 

That car and driver test spells out what people have said for a long time.