Let me first state that I DONT care at all about HP or performance, this is is just for fuel economy!

the car is a 94 EX. which setup should give the best gas mileage

bone stock d15b

OR

d15b with a really small internally gated turbo (maybe 5psi)

OR

d15b with header, exhaust and cai

I know turbos (in vacuum) or bolt ons can increase the effciency of an engine resulting in higher MPG. but would they be ideal for my needs?

and also what transmission CX,VX or EX?

 

bone stock d15b8 cx motor with cx tranny

 

i got 50 mpg with my d15b7 CAI and the standard dx tranny.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chowmien &raquo;</TD></TR><TR><TD CLASS="quote">bone stock d15b8 cx motor with cx tranny</TD></TR></TABLE>

My car is a 94 ex, its a few hundred pounds heavier than what the CX motor was designed for. and would probably be even worse once I have a passenger or any kind of cargo.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">which setup should give the best gas mileage

bone stock d15b</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I know turbos (in vacuum) or bolt ons can increase the effciency of an engine resulting in higher MPG.</TD></TR></TABLE>
They increase volumetric efficiency. They do not increase fuel economy.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">and also what transmission CX,VX or EX?</TD></TR></TABLE>

Or better yet, use an entire D15Z1 or D15B8 drivetrain. Even better than that, just sell your EX and buy a CX or VX. VX, preferably.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">

My car is a 94 ex, its a few hundred pounds heavier than what the CX motor was designed for. and would probably be even worse once I have a passenger or any kind of cargo.</TD></TR></TABLE>

Then I guess a bone stock d15b7 and cx tranny.

 

ok so d15b7 came in the 92-95 DX coupe right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">ok so d15b7 came in the 92-95 DX coupe right?</TD></TR></TABLE>
'92-95 DX coupe/hatchback/sedan, '92-95 LX sedan

 

I would say the D15b (don't know about the tranny) with CAI, headers and free flow exhaust. A freer flowing engine is going to get better gas mileage. The engine may also make more hp, you just have to make sure you don't use the extra hp when you are leaving the stop light. Drive like you did before and you will get better gas mileage.

 

the d15b I was talking about wa steh jdm vtec one.

 

i'd just stick with your z6 little more torque in the lower end than a d15b. that'll help move your pig of a car. other option is trade in your current car for like a dx, cx, or better yet a vx, like said. The D15b get's it's power in the upper end of the power band and if you're looking for fuel economy you may want to stay away from the upper end . lay off the skinny pedal and shift at 3k

 

If you do a lot of street driving as opposed to highway, especially if you live in a hilly area, then you will get better gas mileage from a low boosted turbo than an underpowered engine that requires you to floor it constantly.

I say keep your engine and get an AEM EMS/with UEGO tuned by someone that knows how to tune driveability and has a mustang dyno (allows you to vary load). They're going to lean it out as much as possible on cruise.

 

Everybody already knows that the bone stock would give you the best mpg. Turboing your car is the worst way to go for gas mileage if you have a daily driver, unless you want to drive under 3000 rpms all over the place. Trust me, with a turbo, its not too easy, not like i got one mind you, i just know from talking to other people wtih turbo cars.

 

Sorry, scratch that, the points made here are valid, i.e. u would have to floor it just to pick up decently with such an underpowered motor. One thing, though. A CAI with <U>definitely</U> help your mileage

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shaundrake &raquo;</TD></TR><TR><TD CLASS="quote">If you do a lot of street driving as opposed to highway, especially if you live in a hilly area, then you will get better gas mileage from a low boosted turbo than an underpowered engine that requires you to floor it constantly.

I say keep your engine and get an AEM EMS/with UEGO tuned by someone that knows how to tune driveability and has a mustang dyno (allows you to vary load). They're going to lean it out as much as possible on cruise.</TD></TR></TABLE>

this is what I was thinking.