Modded Mustang Forums banner
1 - 20 of 21 Posts

·
Registered
Joined
·
632 Posts
Discussion Starter · #1 ·
Ok so I'm thinkin about getting a tuner with a custom tune soon. if i do get the tuner i will most likely get some udps along with it. my question is what difference will the octane make in the tune? how much hp and tq will i lose if i stay with regular vs premium? i am trying to decide on udps and tuner or visual mods, and the hp and tq will most likely be the deciding factor. any help on the tuning question would be much appreciated!
 

·
Registered
Joined
·
2,666 Posts
Higher octane gas is more cumbustible...burns easier, as opposed to exploding. Burning is good. Exploding is bad
 

·
Registered
Joined
·
811 Posts
with a good tune im pretty sure you can get a considerable amount more hp and tq out of high octane. but im unsure of the exact numbers.
 

·
So say we all.
Joined
·
594 Posts
I cannot tell you much about the tuner (as it is on my Mustang Bucket List), but I can tell you about my experience with 87 vs 93.

I got this car in May. I only use 1 gas station and I started with 87 octane w/STP fuel additive. I was getting 16 MPG. I stopped using the fuel additive and went to 14MPG. I noticed the 87 octane without the additive was causing a black build up on my tailpipe. I went to 93 octane, cleaned off the sludge and went right back to 16MPG. Ive since had a complete fuel system cleaning and am not getting 20 MPG with 93 octane.

Ive also noticed a slight pick up since. Im not a huge fan of using 87 octane =/. Some people are going to say there isnt a difference or much of one. Some are going to say if youre not tuned to high octane, youre wasting your money. Or only use high octane if you hear a louder knocking (which the manual also says) but I personally, I say use 93 octane.
 

·
Registered
Joined
·
2,666 Posts
Higher octane relates to timing...advancing the timing sqieezes out more power, but also needs higher octane gas
 

·
June 2010 ROTM
Joined
·
1,913 Posts
FWIW...

Dont believe all the HP gains...

Here's the deal. I live near diablo. I bought my 2000 GT a few years ago, BONE STOCK, down to the air filter. Diablo put word out on a local forum that they needed some cars to test on, 2000 GT was on of them. I let them use my car for a few pulls on their own dyno, and I got a free Predator.

Bone stock my car put 236 at the wheels. with the performance tune, it gained a whopping 6 hp.

I"m not saying this is bad, but its nothing crazy...
 

·
Registered
Joined
·
806 Posts
FWIW...

Dont believe all the HP gains...

Here's the deal. I live near diablo. I bought my 2000 GT a few years ago, BONE STOCK, down to the air filter. Diablo put word out on a local forum that they needed some cars to test on, 2000 GT was on of them. I let them use my car for a few pulls on their own dyno, and I got a free Predator.

Bone stock my car put 236 at the wheels. with the performance tune, it gained a whopping 6 hp.

I"m not saying this is bad, but its nothing crazy...
I will say though 236rwhp on a stock GT is higher than normal. maybe your GT just didn't have much room to improve. and on a completely stock car a tuner is not really needed, it will be for fututre mods. And while you got the tuner might as well get a 93oct tune.
 

·
So say we all.
Joined
·
594 Posts
I will say though 236rwhp on a stock GT is higher than normal. maybe your GT just didn't have much room to improve. and on a completely stock car a tuner is not really needed, it will be for fututre mods. And while you got the tuner might as well get a 93oct tune.
And UDPs :cool:
 

·
Registered
Joined
·
632 Posts
Discussion Starter · #10 ·
good stuff guys good stuff... i was hoping someone would have a number (or approx number) but that probably wont happen since most people just go with the 93 octane tune right off the bat. i may email a tuner and see what they say about the differences. i will post what they say, but i dont have time to do it today. thanks for the responses!
 

·
Banned
Joined
·
15,799 Posts
FWIW...

Dont believe all the HP gains...

Here's the deal. I live near diablo. I bought my 2000 GT a few years ago, BONE STOCK, down to the air filter. Diablo put word out on a local forum that they needed some cars to test on, 2000 GT was on of them. I let them use my car for a few pulls on their own dyno, and I got a free Predator.

Bone stock my car put 236 at the wheels. with the performance tune, it gained a whopping 6 hp.

I"m not saying this is bad, but its nothing crazy...
well 2 problems...one its a horrible V8 motor.
second is you used dia-BLOWS
 

·
Registered
Joined
·
3,145 Posts
lmao the 2v is horrible
it aint horrible, it has its place, just like the 3.8 who some think is horrible. I know it is not amazing like the 4v or 3vs but it is still not the worst.
 

·
Danger To Manifold
Joined
·
1,488 Posts
I have the SCT chip which you can swap between modes.

When I was at the track I decided to run a few different tests on it.

I put 93 in my tank and set it to stock. I left it in drive to make sure that the shift points were as close as possible when checking them against each other.

The average time on the stock setting with 93 octane was 16.0
The average time on the 83 setting with 93 octane was 15.7
And my average time on the 93 octane setting was 15.4

I don't recall my average trap speed however.

I know this is not what would be considered a controlled test/comparison but they are all relative enough to give you an idea.
 

·
Banned
Joined
·
15,799 Posts
it aint horrible, it has its place, just like the 3.8 who some think is horrible. I know it is not amazing like the 4v or 3vs but it is still not the worst.
ehh it pretty much is

you know the crap on the floor that wont come off with a mop that you have to scrap off...thats the 2v there

2004 2v GT 8psi-370ish whp
05 3v- 7psi-480+whp

tons of 3vs have hit 400whp all motor. if a 2v hits 350whp all motor its the shock of the world


ford REALLY screwed up 95-02
only thing good from 03 was the termi
which in some ways i think the 3vs respond better to boost then the 4v
 

·
Banned
Joined
·
15,799 Posts
I have the SCT chip which you can swap between modes.

When I was at the track I decided to run a few different tests on it.

I put 93 in my tank and set it to stock. I left it in drive to make sure that the shift points were as close as possible when checking them against each other.

The average time on the stock setting with 93 octane was 16.0
The average time on the 83 setting with 93 octane was 15.7
And my average time on the 93 octane setting was 15.4

I don't recall my average trap speed however.

I know this is not what would be considered a controlled test/comparison but they are all relative enough to give you an idea.
those seem soooooo inaccurate or deffinitly nor where close to a dailed in car. if you gain over half a second off just a tune which is maybe 8-10hp...and gain half a second then clearly something isnt dialed in or true

also where in the world do you get 83 octane?
 

·
Danger To Manifold
Joined
·
1,488 Posts
That was a typo. I meant 87.

As for the times I said that it was as close as I could them to the same conditions, but even with the TCM doing the shifting times will vary somewhat.

It was also spread out over 2 days. The track near my house is so crowded you can only get about 4-5 runs a night if you're really lucky.

As stated, there ware a lot of unknowns and variables but just to see if there was any difference between tunes, there was.

I guess I should have added that information in there for piece of mind but I didn't think I would have to be that detailed about if there was a difference or not just to answer his question.
 

·
Registered
Joined
·
3,145 Posts
I dont know I tried switching tunes. I have just bolt ons and the tuner where it has preloaded tunes. I have an 87 and then I tried the 93 with a manual and i didnt really notice a difference. maybe I will try it again the next tank. I did notice a little bit more response in my butt dyno, but that could be my imagination.
 
1 - 20 of 21 Posts
Top