Honda CRX Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
46 Posts
Discussion Starter · #1 ·
I talked to a guy the other day in town who has a CRX si that he dropped an HF motor in. I can't wait to see it on Friday as I want to drop an HF motor in mine too :)

Anyway, he's getting mileage in the 30s as opposed to the +40s

Is this strictly a weight issue or are there other factors involved like ECUs and other things? He said he went to a lot of trouble to get the motor working, lots of wire relocating, adding some emissions bits, etc.

All help is appreciataed,
 

·
Administrator
Joined
·
16,562 Posts
Gearing, weight, driving habits, ECU, aerodynamics, etc will all come into play. The HF was sold as a package deal. If he's using the Si trans and Si (PM6) ECU, and driving it to extract the accustomed around-town performance of the Si, mileage certainly won't match up to that of an HF.

I have no idea what you would have to do to get a D15B6 working in your dx, though an MPFI swap would approximate it. Personally, if I was looking for more mileage, I would go with a D15B7, D15Z1 or even a JDM D15B.
 

·
Registered
Joined
·
20,350 Posts
lysinger said:
I talked to a guy the other day in town who has a CRX si that he dropped an HF motor in. I can't wait to see it on Friday as I want to drop an HF motor in mine too :)
How sad is it that we live in a time when this is exciting,
Detuning the higher trim level vehicle. :D

Is this a new trend?
Next up, high demand and high prices paid for HF, Cx/VX (never can remember which one is the "Economy model) & HX motors!
 

·
Registered
Joined
·
1,480 Posts
baker423 said:
lysinger said:
I talked to a guy the other day in town who has a CRX si that he dropped an HF motor in. I can't wait to see it on Friday as I want to drop an HF motor in mine too :)
How sad is it that we live in a time when this is exciting,
Detuning the higher trim level vehicle. :D

Is this a new trend?
Next up, high demand and high prices paid for HF, Cx/VX (never can remember which one is the "Economy model) & HX motors!
Nothing wrong with that! Ive always wanted a crx to make it fuel efficient. Yet my plans are to get the HF and swap it so it doesnt take fuel. :wink:
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #5 ·
baker423 said:
lysinger said:
I talked to a guy the other day in town who has a CRX si that he dropped an HF motor in. I can't wait to see it on Friday as I want to drop an HF motor in mine too :)
How sad is it that we live in a time when this is exciting,
Detuning the higher trim level vehicle. :D

Is this a new trend?
Next up, high demand and high prices paid for HF, Cx/VX (never can remember which one is the "Economy model) & HX motors!
It's all a matter of priorities :)

This guy did it for the low end torque around town. I'm planning on doing it to try my hand at building an 80mpg (freeway) civic. Serious law of diminishing returns and big bucks once you add the turbo and lighten up the bottom half of the motor, but cars are a waste of money.

I've already built a fairly fast Impala and want to go the other direction on the civic and then mod it to run E85.

It's a whole lot harder to build a fuel efficient car than a high performance car.
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #10 ·
I saw this guy's CRX yesterday and I found out his mileage problem. A large THULE bike rack with 2 bikes on it :) Nice guy, bought an HF head, intake and throttle body from him. Now I just need the harness CPU, and tranny. Oh, and rebuild my spare block :)
 

·
Registered
Joined
·
20,350 Posts
daveb91 said:
baker423 said:
How sad is it that we live in a time when this is exciting,
Detuning the higher trim level vehicle. :D
who would think this is exciting??? OK I just picked up a Corvette that i will be dropping a 2.8 v6 in. YEAH!! :lol:
Or...."I just picked up this Sweet Hemi 'Cuda and i am gonna dump that gas guzzling Hemi and drop that sweet Neon motor in it for better milage." :lol:
 

·
Registered
Joined
·
166 Posts
The Vette and Hemi Cudd;s were performance cars so you want a high performance engine, but the CRX is an economy car (Honda most efficient fuel car ever), with the HF rating at over 60 mpg.

So putting a smaller engine in the Si to get better MPG makes perfect since.

You end up with a car with all the Si goodies and the better fuel economy. And 45-50 MPG with the HF engine in a Si compared to the 30-35 with the Si engine is a lot when you multiply that by the price per gallon.

IMHO

Bob
 

·
Registered
Joined
·
166 Posts
The Vette and Hemi Cudd;s were performance cars so you want a high performance engine, but the CRX is an economy car (Honda most efficient fuel car ever), with the HF rating at over 60 mpg.

So putting a smaller engine in the Si to get better MPG makes perfect since.

You end up with a car with all the Si goodies and the better fuel economy. And 45-50 MPG with the HF engine in a Si compared to the 30-35 with the Si engine is a lot when you multiply that by the price per gallon.

IMHO

Bob
 

·
Registered
Joined
·
58 Posts
the Hf motor really has nothing to do with gas mileage in the HF, the main factor in the good gasmileage is the HF tranny. i drive an HF and about a year ago i swapped the stock motor for a d15b7 but left the HF tranny, if anything my mileage got a hair better because i was flooring the motor much less just to get around town in traffic and **** and up hills. it was'nt until i put an Si tranny in it that my mileage dropped down to like 30 mpg.
 
1 - 16 of 16 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top