lx to hf expectations - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 04-10-2008, 07:15 PM   #1
Registered Member
 
civic lover's Avatar
 
Join Date: Oct 2007
Posts: 123
Country: United States
lx to hf expectations

What can I expect to gain for mpg with the hf conversion? I understand epa is 50 plus but you have to remember i am toting around a few hundered pounds more. Is there anyone out there with some good gas logs of the same conversion? Thanks...
__________________

civic lover is offline   Reply With Quote
Old 04-13-2008, 07:09 PM   #2
Registered Member
 
civic lover's Avatar
 
Join Date: Oct 2007
Posts: 123
Country: United States
someone has to have a log on here...
__________________

civic lover is offline   Reply With Quote
Old 04-13-2008, 07:21 PM   #3
Registered Member
 
Hateful's Avatar
 
Join Date: Nov 2007
Posts: 321
Country: United States
Send a message via AIM to Hateful
I know nothing about civics being I'm one of the few without one. I do remember the EPA estimate allowing for 300lbs of passenger and cargo. I also have read that every 100lbs of extra weight decreases mileage by 1 mpg.By calculation the weight difference you may be able to come up with an estimate.
Hateful is offline   Reply With Quote
Old 04-14-2008, 03:42 PM   #4
Registered Member
 
Join Date: Oct 2007
Posts: 298
Country: United States
There is also aerodynamics to consider here. An LX is not going to slice through the air as easily as a CRX.
StorminMatt is offline   Reply With Quote
Old 04-15-2008, 10:59 AM   #5
Registered Member
 
civic lover's Avatar
 
Join Date: Oct 2007
Posts: 123
Country: United States
I know that is why I was wondering if there were any logs out there. (I am still new here). It is hard to calculate the weight and aero drag and so on. It is much easier to calculate based on some real numbers from other people.
civic lover is offline   Reply With Quote
Old 04-16-2008, 12:57 PM   #6
Registered Member
 
Join Date: Aug 2007
Posts: 107
Country: United States
I don't think the gas savings would pay for the work unless you do it yourself. Even then I think the savings would be pretty marginal. Sure my HF gets 65 MPG on a flat surface at 65 MPH but only just maintaning speed. I only got 45 today in a 20 MPH headwind on a run that would normally get me 55+. You would not want to use the HF tranny in a 300 lb heavier car. I figure a LX with a HF head would get you maybe 40 on the freeway and around town would drop your average. If you did a bunch of aero mods it would do better but I don't know how much better than leaving the engine alone with those mods

I think some kind of metering for the gas consumption would probably make a bigger difference with some practice. A duty cycle meter on an injector wire, $19.95 at sears, so you could figure out your consumpion per hour would do. You could also try the DIY mileage computer from the how to section or wait for them to figure out the one they are working on at ecomodder.com

For your money doing the federal VX swap would be a better idea since you already would have to modify your wiring for MPFI. You could pick up a complete swap for $400 plus the O2 sensor or so. I think the 62 HP HF motor would end up working too hard and might even cost you extra gas if you do a lot of stop and go driving.

Is the new owner of the Frankencivic on this site to fill us in on how a VX/LX performs?
FritzR is offline   Reply With Quote
Old 04-17-2008, 05:52 PM   #7
Registered Member
 
civic lover's Avatar
 
Join Date: Oct 2007
Posts: 123
Country: United States
I hear you, but if you were to add a passenger to your rex would your mileage significantly drop? If so then this swap would be pointless (because of the 300 lb difference). I did do some weight reduction to narrow the gap. Minnesota also did some wonderful weight reductions too, due to the salty roads in the winter. I have the whole HF swap ready to throw in (from a parts car going to the crusher), but am still contemplating. In other words it wouldn't cost me about 100 bucks said and done. I do feel however by doing the mpfi swap with the hf ecu I would net some mpgs.
civic lover is offline   Reply With Quote
Old 04-18-2008, 11:00 AM   #8
Registered Member
 
Join Date: Aug 2007
Posts: 107
Country: United States
Well if you already have all the parts I say go for it but stick with the original transmission. It's not the weight that will hurt your freeway mpg much it's the wind resistance. The hf motor also runs smooth down to 1000 RPM. From my experiments with the supermid it's best to accelerate pretty hard to get out of the low gears. 20 MPG is the best you can get in 1st so get out of that gear fast. Race it up to cruising speed and skip a gear and cruise seems the best. Take it up to 35 in 2nd and then go straight to 4th and cruise.
FritzR is offline   Reply With Quote
Old 04-18-2008, 02:51 PM   #9
Registered Member
 
civic lover's Avatar
 
Join Date: Oct 2007
Posts: 123
Country: United States
yeah I shouldn't have to worry too much about highway or interstate speeds cause most of my driving is country roads that are flat. I guess someone needs a gas log on here with the swap in a sedan. I guess it will be me. I guess you could look for me starting my log in about June.
__________________

civic lover is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Is there a OBDI or OBDII conversion for older vehicles? kozaz General Fuel Topics 3 11-13-2007 08:32 PM
Where can I get a superMid? oneinchsidehop General Fuel Topics 2 10-05-2007 04:58 AM
XFi mirror caps? baddog671 General Fuel Topics 4 07-10-2007 03:51 PM
VX Head Question GasSavers_scostanz General Maintenance and Repair 8 02-17-2007 04:27 AM
thought this article was interesting bagpipe goatee General Fuel Topics 1 09-06-2005 10:57 AM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 12:08 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.