my friend said i should put higher octane gas in my car because it'll ruin my fuel injectors...i put the lowest one in my car which might be 87 or somewhere around there...i have a '93 mustang 5.0 what do you guys think on which octane i should use?
which octane?
- Thread starter 93Stang50
- Start date
- Status
I'm not sure for the 5.0's but I know the 4.6 SOHC cars I ran 87 stock, but 93 after the head swap.
87 should be fine, unless you get higher compression or forced induction.
You can run whatever you want in the 5.0 if its stock...however the higher the octane the cleaner the fuel will burn and the better gas milage you will get and posible a few more HP's :burnout:
Good points here, I usually swap tanks rotating between 93 octane and 89. (super and mid-grade) I find it less expensive to do this and the performance of the car doesn't really suffer all that much:burnout:
Please explain yourself here...higher octane fuel burns slower than lower octane fuel. If you don't have the support or need for higher octane fuel (i.e. high CR, advanced timing, hotter ignition, high engine temperature, etc) why run higher octane? I guess I don't understand why high octane burns cleaner...
Run the lowest octane you can without detonation. Anything else is a waste of money. Some engines can automatically advance timing and adjust for different octane fuel to some extent, but not the 5.0.
If you don't ever detonate running 87, I don't think you'll get much out of running 89...but advance your base timing a bit and you will!
I run 93 only.
The ONLY difference between 87 and 03 is it's resistance to burning. You make the call... For me, I run the lowest I can before it starts to ping.
Doubtful. I've never seen any increase in performance or mileage from using it on any of my mustangs. (The n/a ones anyway)
sawed-off
Banned
Okay, why in the world would you even contemplate using cheap gas in a preformance oriented car? You'd essentially blowing a foot off, to run a marathon. In this ballgame, you shouldn't even know about anything other than premium. This is SVT Performance, not "Ford mileage maker forum". Low octane fuel just doesn't aide your cause or desire in the long run. You're in for some maintenance issues if you do use it. It's just not worth it. 
Last edited:
You have a lot to learn then... (You subscribe to the more$ =better theorem. I like guys like you when I am selling stuff at the swap meet.) You need to read up on this. All the car mags have done plenty of stories explaining why you are wrong. Check out back issues of Car Craft, Hot Rod, Motor Trend, and MM&FF. They have all run stories explaining why higher octane does nothing if it isn't REQUIRED. IF you can't use the higher octane benefits, you are wasting your money. It's not like synthetic oil where spending the extra money is giving you a benefit...
sawed-off
Banned
You couldn't sell sh*t to a fertilizer salesman, and opinions are like as*holes, my friend. I think having a dozen years in circle/dirt track racing makes me quite qualified to a magazine enthusiast. You shouldn't be so quick to streotype. I've never been a subscriber to the "more is better" theorem. If you want to run low octane in a high performance engine, go right ahead, it's your car. There's no way in hell that I'll use a low octance fuel in, an engine that is sublect to the stress/heat that a racing or high performance engine is subjected to. You'll wind up replacing cranks, pistons, and engine wear goes up along with higher operating temps, as a by product of preignition/detonation.
Read it again. I said when NOT REQUIRED. Either by the engine builder or the car manufacturer. A 1993 Mustang DOES NOT REQUIRE higher octane. I have been building engines and drag racing for more than 12 years too. I also WORK for FORD. (You know, the guys that built the car...) I feel qualified to answer this statement. I will reiterate that a 93 Mustang DOES NOT NEED high octane, unless you add forced induction or really crank the timing.
Yeah, a 12 to 1 dirt track motor definately needs higher octane. But a stock Mustang driver would be wasting his money and lowering his performance. My answer would be intirely different if it was an 03 Cobra or if he had a Forced induction or high compression motored car.
BTW, didn't mean to sound harsh on ya, but ease up on the moderators...
:beer:
Yeah, a 12 to 1 dirt track motor definately needs higher octane. But a stock Mustang driver would be wasting his money and lowering his performance. My answer would be intirely different if it was an 03 Cobra or if he had a Forced induction or high compression motored car.
BTW, didn't mean to sound harsh on ya, but ease up on the moderators...
:beer:
Last edited:
sawed-off
Banned
Maybe the moderator needs to swallow his own advice and put his ego in his back pocket. You quoted magazines, when you say you work for the Ford Motor Company. For all I know you're a maintenance repair technician. The man plainly stated that he had a Mustang with the 5.0 engine. Now, this being the SVT Performance forum, the advice on octane rating was based on that, this being a performance forum. I will disagree with you on many things as such. An engine under load from hauling heavy payloads, to one that sees performance oriented use will require a higher octane to maintain optimum performance. Cam timing, cylinder head flow, outside ambient temperature, all will affect an engines need for octane. This same thing holds true for the plumber in his van with it's low power 305 V8, hauling around 300lbs of supplies and equipment in the mid July heat. So guess what, he needs more octane to prevent detonation, even though his motor in his van is not a performance motor. Now on the other hand my lawn mower does and cannot run well on 93 octane fuel. It works with only regular 87. Manufacturers recommend things all the time, but that doesn't mean it's gospel, kinda' like Firestone tires.
Um, yeah, ok. Keep tell him to keep putting 93 in an engine that doesn't need it. Whatever. I presently own 4 5.0 Mustangs, and I haven't experienced detonation in any of them on 87. I also quoted several magazines that had documentaion from engineers on the subject. I also quoted Ford's recommendations based on the observations of their engineers. Ok. You can have your opinion. It's just wrong. At least it wouldn't hurt anything to spend the extra money. It's just a waste...
1) <snip>Cam timing, cylinder head flow, outside ambient temperature, all will affect an engines need for octane...<snip>
I believe that's what everyone is trying to say! All of those factors can contribute to detonation, which would require higher octane gas. You are contradicting your own point by saying to always run premium fuel. So back to the original point, you only need to run enough octane to not detonate. If a stock Mustang 5.0 doesn't detonate with 87, it's not going to run better with 93. If the E350 service van pings with 89, he's got to run 93. Same thing applies to your lawnmower as you correctly stated.
2) Also, I don't believe anyone mentioned 'cheap' gas...I think everyone here knows there's a difference between 'cheap' gas and 87 octane gas.
I believe that's what everyone is trying to say! All of those factors can contribute to detonation, which would require higher octane gas. You are contradicting your own point by saying to always run premium fuel. So back to the original point, you only need to run enough octane to not detonate. If a stock Mustang 5.0 doesn't detonate with 87, it's not going to run better with 93. If the E350 service van pings with 89, he's got to run 93. Same thing applies to your lawnmower as you correctly stated.
2) Also, I don't believe anyone mentioned 'cheap' gas...I think everyone here knows there's a difference between 'cheap' gas and 87 octane gas.
Thanks blown 306. You hit the nail on the head exactly. We all obviously agree when you should should go high octane when you REALLY NEED higher octane. But ALWAYS is not the answer.
- Status
Users who are viewing this thread
