Fuel mileage

[LS1_ws6]

Well I installed longtubes about 3 months ago and before that I had great fuel mileage but know I filled up half my tank and only got 40 miles out of it I dont push the car too hard everytime most of the time i take it slow. any help in what could be wrong or is this normal?

[Zinergy]

Get a tune, sounds like your running rich thanks to the long tubes. Did you get the 02 extentions?

[LS1_ws6]

Get a tune, sounds like your running rich thanks to the long tubes. Did you get the 02 extentions?

yeah i wanted a tune and I did get o2 extension and have a ory. and the exhaust always smells like gas. should the tune help

[FutureWS6]

the tune will help alot

[Zinergy]

yeah i wanted a tune and I did get o2 extension and have a ory. and the exhaust always smells like gas. should the tune help

yes, the tune should get you pretty close to your old gas mileage and unleash some hidden power. Too many mods will confuse you stock ecu and casue it to run rich to be safe and not allow for detonation. A good tune will still keep your engine safe.

[shady milkman]

if you are only getting 40 miles to a tank...you got some serious problems ....

[Zinergy]

if you are only getting 40 miles to a tank...you got some serious problems ....

Might not be serious, the ecu can do crazy things. My buddy didnt have an o2 in his mustang for a couple weeks and at teh time he was driving 5 miles round trip a day for work and a full tank wouldnt even last him a week. He also only drove to work and occasionally im sure to a local fast food place on lunch since he didnt have a liscense.

[shady milkman]

Might not be serious, the ecu can do crazy things. My buddy didnt have an o2 in his mustang for a couple weeks and at teh time he was driving 5 miles round trip a day for work and his car wouldnt even last him a week. He also only drove to work since he didnt have a liscense.

true ....but i would think it might be 02 related in terms of bad 02s etc or a bad extension

[Zinergy]

true ....but i would think it might be 02 related in terms of bad 02s etc or a bad extension

Yes but you never know what the ECU is thinking until you data log it.

[c5z28]

Check fuel lines, cap, tank?

[JunkyardZ]

I actually picked up about 1 mpg with my install. And yes, you will smell gas.

[RyanJM]

You will smell some gas since you have no cats but my 02's were deleted since the sims can go bad nd I got vette 02's so I didn't have to waste money on extensions, new exhaust why not install new 02's while your at it. I did lose some gas mileage when I 1st installed them and them my fuel pump was on it's way out so I hd a new pump installed and a dyno tune, still loss some mpg and had a heavy gas smell, so my friend who had a Vette shop did a street tune and leaned it out since it was too rich for dd and actually had to install new plugs because of the rich tune. Now I have 3.73's and a street tune and average 18 to 20mpg on cruises depending on how hard I'm pushing it. If I had a 6spd like my friend I'd probably be getting 24 or 25 but would hve done 4.10's. Get a good tune and the car will get better mileage and should gain a few hp since the timing can be bumped up a little and if you have an A4 they can tune it to shift firmer, my car shifts hard enough to spin th 275/35r18 BFG Nt's from 1st to second anytime I'm over 3/4 throttle and at WOT my car is set to shift at 6000rpm.

[LS1_ws6]

Would a tune by Frost work out or will i need something else? this is my dd and want the best fuel mileage i can get without losing hp.

[RyanJM]

I never had him do a tune for me but hear good things on the forum about him. His mail order tune prices are alot less than the shops in my area. My tuner had my car almost perfect with just using a tune off a vette that had almost the exact same mods as me just different CAI, headers, and catback but none of that made a huge difference. Later we pulled a little more out of it by driving around with a wideband 02 and he altered a few settings. Pulled a little harder up top and had to reset the computer for my 3.73's that I had just put in.

[LS1_ws6]

So will this take care of my problem or can it be something else

[RyanJM]

From what you described it sounds like what my car was doing. Anytime you install lt's and ory pipes with a decent intake your flowing alot more air so the computer is most likely overcompansating. Everyone I know who has lt's has had tune done and their car ran better.

[Cutlass]

Yep go with a mail order tune from Frost.

[LS1_ws6]

Does it take them long to tune my pcm?

[RyanJM]

Does it take them long to tune my pcm?

Took my guy 10 to 15 min if that.

[LS1_ws6]

So the longest part would be shipping?