Let's here them...

I'll go first....

My Whole Car..kind of not joking but I do wish I would have bought a 2001 Cobra. I definitely regret my convertible.

Mods I regret:

• Summit Racing Control Arms (though a gift I regret asking for them) - Bushings failed, had to buy new control arms anyway. Went J&Ms
• FRPP C springs - Too Stiff....should have gone with the Bs
• Comp Cams XE268H - No top end, not much more power than stock. Should have gone Comp 270s or waited for my CMS Stage 2s.
• I regret getting greedy with my nitrous...should have kept the Zex 125 pills with the nozzle and got a dyno tune.
• SR Short Throw Shifter...I ended buying an MGW anyway.
• BBK Shorties...should have gone longtubes.
• Some days I regret my 4.10s...most of the time I don't. living 40 miles from work now (instead of 9) has aided in my regret...

I do not regret my bolt ons like most do...I like tinkering with my car and having something to do. Bolts allowed me to do that when I didn't have a garage. Helped my bordem before we had kids.

I regret buying a mustang the previous owner had a moon roof installed on. Besides that ZERO REGRETS.

Underdrive pullies.....

Waste of time and $180 or whatever I paid for them. I never noticed the advertised +8 to 10 hp, we'll maybe for like a day lol - mostly just placebo. I had aluminum BBK's, which after about 30K the water pump pulley had a groove worn into it from the belt that happened so gradually I never noticed until the wear had become lopsided and cost me a new tensioner and also took out the bearings in my alternator. When it was all apart for the tensioner I just happened to give the w/p a spin by hand and noticed the uneven wear and a spot that was less than paper thin. Still have the other two pulleys on (w/ stock w/p pulley) and seems to be fine.

Sportlines springs. Sort of.

I love love love the drop and the way the car sits, and staying flat in corners is nice. But I'm not 30 anymore, I'll be 40 in a couple months (yes, that's really how long I've had them) and the ride quality kinda beats you up on long drives. A little more compliancy would be nice sometimes, that's all. If I had or ever have it to do again, will definitely go with a progressive spring.

And Jon, be careful what you say about 4.10's. We can't be having any dissent within the ranks there bud.

it's not often but when I fill up twice a week it gets old...I'm still glad I went with them.

-Eibach Sportline springs - because they ride like a tobacco wagon and even as a car enthusiast I hate them.

- 3.73 gears - because my fuel economy took a noticeable nose-dive and I only picked up a tiny little tenth or two in the quarter mile. Should have left it stock. Car screams for help while cruising at 80 MPH now.

Otherwise I've been surprised with the bolt-on mods and the 40 horsepower increase I got from them. I never imagined that those little things would really add up like that.

I know you don't want to believe me but a stall converter in your car will help those 3.73s out A LOT. Just sayin'

Man, I dont see why you guys are losing fuel mileage from gears. Each time Ive swapped gears in my car, I went from 3.08 to 3.73 and gained a few mpg. Then did an irs swap and went from 3.55 to 4.10 and gained mpg with that. I always cruise at 80mph and dont have a complaint in the world. At 368 rwhp high compression 2v with huge cams, I still got 18 mpg and could have gotten more with a little fine tuning of my afr.

So far none, on the mustang (though had I installed that MMD styling bar, I think I would have regret that, at this point). I am really trying for the less is more approach with this car.


Going over a decade back to my T-bird the 2 most overrated mods in my mind are:
+1 on the under drive pulleys. I personally, don't think they added anything and really just messed with my cars audio system.
also My MSD DIS4 ignition. Complete waste of time and money. with my set up there was no benefit, but I was young and stupid, and thought it would do something.

I am only getting 18mpgs now with the summer blend of gas. Winter blend I was lucky to get 16mpgs. I'm almost all highway. My car has never gotten good mileage though, even before all my mods and such. When I was mainly city I was getting 14-15mpgs.

Aftermarket clutch
- I wish I would have just put a stock replacement with an OEM TOB in my car. A bolt on car doesn't need a stage 1 type clutch anyway. Mine is a spec flywheel and spec stage 1 clutch kit. It feels heavy and becomes a pain to drive when used as a daily. The TOB also obviously went out quickly, and now I am thinking about dropping the transmission again and just going back to stock everything clutch wise to try and get some of the stock comforts back.

Steeda shiftier
- I just want to simply try out the MGW unit. Haven't really had many problems with the steeda unit.

Mac CAI
- I wish I would have bought one of those older JLT units. They were more expensive at the time which is why I bought the Mac unit but the clean look of the black JLT units looks so much better then the flashy cheap chrome look under the hood.

BBK Shorties
- I wish I would have spent the money on other things.

I just added headers and dyno tune last week. I was a little apprehensive going this step with my DD. I liked how it ran and sounded previously with an aftermarket catted H pipe and dataloged tune.
It's definitely different now and I'm still getting a feel for it and I'm liking more my decision. I reset the mpg read out last Thursday and it hasn't settled in yet. Right now it's hanging where around where it was, around 21.5.
JohnR. If I had to fill up twice a week, I'd have to start looking at getting a beater. Lol.

The tuner said if I'm considering anything else, he said 4.10s. I think for a DD, 365/yr, that would kill me.
Also, when I leave work now, I'm checking for a way home with as little stop and go traffic as possible. Even if it is longer. Summer heat soak sux.

I won't say I regret it but I will say I'm not 100% onboard for a DD..........yet. For a weekend car? Hell Yea!!!
Let's just say hood vents might be in my future instead of gears. Lol

It's in the budget already. It's actually a wash since my commute got longer, my wife no longer has one (stays at home).

I actually had a DD for awhile..a 1995 Camry...but I let my sister borrow it and she totalled it a few months ago.

Once we get a minivan, which will proabbly be next year, I'll have my wifes car as a DD. That's the plan anyway lol....

Are you driving your 368 hp and 4.10's for long stretches on the highway every day and you saw an increase in mpgs? Or you saw an increase running errands around town? Surely one would get better mpgs cruising at 1800 rpm vs 2500.
I wish I had went with 331's or so instead of the 3.73's for the same reason everyone else regrets too steep of a gear. Three shifts to 60 mph. At the track I'm in second gear pretty much right after the launch, y'all know the rest. Since it doesn't get driven much I can live with them but if it was a daily life it'd suck.

My drive is 75 miles one way to work. Traffic speed averages 80mph. When I had 3.73 and just a small stage 2 cam I was averaging 23 mpg on that trip. With the latest engine/gear setup I was averaging 18 mpg. Cruising right around 3k rpm. With 3.55's I was getting 16-17 mpg. I got a consistent 18 after the gear swap. I also came through the traps in 3rd gear with 4.10's.

1800 wouldnt necessarily get better economy that 2500 if the engine load was greater. Fuel mileage has a lot to do with engine load. In neutral holding 2500 rpm will get much better fuel economy than driving up a hill at 2500 rpm. Engine load and efficiency are the two main contenders in fuel mileage and if you have a wideband you can watch that on your afr gauge.

The big reason people see decrease in fuel mileage is because your tune is setup for old gears and at higher rpm it is expecting different load values where target afr and fuel map may not be optimized for the new gear setup.