I was wondering how many mods can still support the regular fuel without going to 91 octane? Is there a way to get a bit more power and have better throttle response and still use 87? Cheaper gas is always better.

 

Well, add'l mods will still be beneficial, even with an 87 tune. If it's an auto, the reduced throttle lag from the tune will make the tune worth it by itself. Get a CAI while you are at it. Better exhaust will enhance performance (and create a better sound), even at 87. When I had the 93 Xtreme tune on my 4.0L/auto vert, I tried the 87 tune and noticed the difference. I decided the increased performance was worth the add'l $3-4 per tank for 93 octane.

 

You can use 87 till you get a tune that's meant for 91 or 93 octane. I know in either the MM&FF or 5.0 mag, they dyno'd a stock 05 mustang with 87 octane. Then drained the tank and put 91 octane in it and it gained 5HP to the wheels. Later they did the same to the 4.0 V6 stang and it lost 3HP. Only cause the V8 has VVT and the sixer doesn't.

 

The only time you NEED to increase your fuel octane rating, is if you do a mod that increases your compression ratio. For example, modified heads or new pistons that raise compression, or if you get forced induction like a supercharger, turbocharger, or Nitrous Oxide.

If you don't have any of those things then 87 octane isn't required at all.

Now then, many of us choose to get a high-octane tune, which has the ignition timing advanced. This makes more power, but it too requires the higher octane gas.

Keep in mind that even though higher octane gas is more expensive, this is still one of the cheapest HP mods out there! I don't know where you live, but in the USA 92/93 octane gas is typically $0.20 more per gallon than 87. So, if you assume that you drive 15,000 miles per year, , and you get 20 mpg, you're looking at only $150 per year. That is very cheap compared to most mods out there!

 

20mpg. HA!

 

20mpg?! i get like 13!!

 

Yeah I don't see the 20mpg since I added the CAI tune and exhaust [sm=smiley2.gif]. Most of the driving is in town too which helps a ton!

 

How the heck are you guys driving?

My driving is about 60% city and 40% highway. Last fillup was 21.1 MPG (calculated by reciept, not the computer display). I could probably get a couple more if I really babied it, but what's the point??

Mods are in my sig,

 

99% city, and the computer says i average 14.3

but the last time i drove, i reset it, and i had to drive to my friends house with like 1/8th of a tank and i got 21.2 city. shifting at like 2k. he lives like 15 miles away too. [sm=happy046.gif]

was a pretty boring drive though -_-

 

What city are you in to get 21.1 MPG? I drive 46 miles a day to and from work in Los Angeles, 60% surface streets (which, in my case, is faster than the freeway) and 40% freeway. Of course, LA is legendary for traffic, so I'm getting beat up! I'm lucky if I get 15.5! Usually around 14.5 - 15 MPG.