Hello all! Looking for advice. :)

Hiya all, I bought a V6 about 2 months ago. It came from the dealer as a 'Southern California Special'. Basically Pony Package, Interior Upgrade, Rally Stripes, Chrome exhaust tip and 'SCS' gas cap emblem on the back.

So far I absolutely love it. I drive pretty mellow on the whole, but I am interested in doing some mods to increase the MPG (with added torque/hp of course ) I'm currently getting about 18.5 MPG... the daily drive is half freeway, half city street... although sometime the freeway is worse than the street.

I live in So Cal and want to keep it street legal, so that does limit my options to some extent.

I know the K&N FIPK filter has been approved for the 05 V6, so I'm sure it'll pass on the '06 next year. I also know that the JBA headers are street legal in CA. After that I was thinking about possibly going with a dual exhaust or maybe just a freer flowing single...maybe a pulley kit too.

Any thoughts on which of these would require me to get a retune? I'm interested in doing the mechanical work myself, but I have no clue what is needed to do a retune... do you have to take it to someone with a dyno? Can you retune it yourself fairly easily with a Diablosport or SCT Xcal2?

Any opinions would be greatly appreciated.

Thanks all

It's my understanding that any mod you do that makes your engine more efficient (increase intake efficiency, exhaust efficiency, combustion percentage) will increase MPG if it is driven the same. The net result will be greater torque and as stated by a gentleman at Steeda in an article I read, more torque equals free gas mileage.

Thanks for the opinions. I probably will stick with the K&N filter due to the strict requirements in CA, but I'll check and see if the others are street legal.

I'm definitely not expecting miracles, but 3 mpg increase is a 16% gain given that I'm getting 18.5 now... that seems worthwhile to me.

Besides, it'll be a lot easier to get the wife to 'sign off' on some of this stuff if I can tell her that it'll save money on gas over time too

Any other thoughts on if headers would be worthwhile without upgrading the stock muffler. Would those mods (headers and/or mufflers) require a tune?

Thanks much

Good question

A lot of it depends on numbers I don't have... I was looking at an article where they upgraded the headers, muffler (single axle-back) and air intake and retuned to use 93 octane gas http://www.jbaheaders.com/articles/50Mustang_306.pdf.

In this article, the torque increase was about 14%. I'm not going to go with 93 octane gas, and since I'm probably going to use a K&N filter, it might not have quite the airflow, so let's say mine only goes up 10%. If that 10% correlates directly into gas savings (not sure if it does), I'd go up around 2 mpg (sounds reasonable )

Now if you divide the miles driven per year (15k) by MPG before and after. You get 15k/18.5 = 810 gallons and 15k/20.5 = 731 gallons or about an 80 gallon per year difference. Given the fact gas is running over $3/gallon in So Cal, I'd estimate I'll 'save' $240 per year.

The cost of the headers is ~ $400, air intake ~ $200 and muffler ~ $200... if I can do the install myself and then get a tuner for maybe $300, I figure I'd pay for it in about 5 years. If I have all the work/tuning done, the payback would be a bit longer.

I really love the look of this car and I'm planning on keeping it for quite a while... but even so, while the gas savings would be nice, it'll be sweet to have the extra performance too.

So assuming that it's worth doing there are still a few things I'm not sure about...

1) Will the K&N filter require a retune (I'm thinking no)
2) Are headers worth it without getting a freer flowing muffler
3) Will headers require a retune
4) Will the exhaust require a retune
5) If any of these require a retune, can I do the retune myself
6) What would I need to do the retune (other than a tuner)
7) How do I do the retune (is it all in the tuner instructions?)
8) Even if I can do the retune myself, is it worth getting it professionally done at least once?

Thanks for all the thoughts, please keep em coming

Thanks for the answers

So it sounds like I should be able to install the K&N FIPK (I checked and it is currently the only air intake mod that is CARB certified for the 05), then the muffler and then the headers and the stock tune should be able to handle it. I can then take it in for a custom tune at my leisure.

I really appreciate all the help... more input would be appreciated

Oh, one other question... if I get a professional tune do you lose MPG to gain the HP? Or does the optimization just make the engine more efficient like the physical mods do?