My current 88 Hatchback Civic DX has seen it's better days. It as survived ice storms, and several Ohio winters, but at last the chassis was now shot, and rusted beyond recognition and the car needed replaced. Earlier in it's life the hatch got 44mpg on the highway, and I wanted a new daily driver that would better that with today's gas prices. I decided my search was for a CRX HF. They have been know to get over 50MPG bone stock. They feature a reduced curb weight, longer gears, and less power. An 88HF was to me the "holy grail" of CRXes for it's light weight. Lighter than any other year or model of CRX. At 1819lbs it stock was over 300lbs lighter than my KRX was when it was stock being a 89Si. That car has gone through a severe diet though to get it close to 88HF weight. This time I wanted to start out right.

I found a rust free California CRX HF on craigslist, and arranged for the guy to pick me up at LAX, and I flew to California, and got the car. Ironically 1 day before my flight left my Mugen Pro.2 bumper for my KRX came through customs, and was in LA, and available for pickup so I ended up bringing it back too. The goal of this thread is to improve upon the gas mileage of the car. During the trip back the car had a CEL, and threw the code for the EGR valve. Also it was running rough like it was out of time. My best mileage on the way back I only got 41mpg, and the worst was 29mpg through the AZ mountains. I later found out that it was off a tooth on the timing, and that was my first task to tackle once home.

1st State conquered on the way back. In AZ a few hours outside of Phoenix.

Don't see epic views like this back home.

The next day I was at my friend's house in Phoenix. We jacked up the car, and inspected my purchase. We also adjusted the drums so the e-brake worked, and I straightened out the bumpers from one of the previous owner's lack of parking prowess.

Note my Mugen Pro.2 bumper in front of my friend's hatch.

Brian giving his approval of my purchase, as we further inspect it.

The next day I saw this 780whp K series powered street legal beast. It was just tunned at Locash Racing. Notice the AFI intake and turbo manifolds, and the new Hasport 94A durometer mounts featuring red urethane.

A few steps away from Locash Racing is Hasport. The place my friends I stayed with work at. Brian my friend above, and his brother Chris, both work there. Brian makes the harnesses, and Chris answers the phones. I am the goon posing in the pic below.

The next pic sucks, but I have 90-91 tails now I scored for $40, plus I sold my 88-89s for $20 to Brian he needed them for his 88 Si he just bought.

@ night in Phoenix. It is Feb and it was still 50's at night. Only half of Brian's cars are here, and the place is still cluttered with Hondas. 90 Si hatch, and my HF in the garage. Brian's 91 HF, and Chris's 00 EX in the driveway, and Brian's 89 DX 4 Door in the road.

Mugen bumper secure for the rest of the ride home.

Rolling down the 40 on my home....

In St. Louis over halfway home. No stopping me now.

First day home. I introduced my new Polar White Hf to Polar conditions.

These pics are the first day home. I went snowboarding with a friend, and I decided to snap some pics on a scenic hill. Ironically my friend from Phoenix used to live in Ohio near me. He flipped a 88 hatch on this same hill. He was doing excessive amounts of speed, and lost control. His roof was level with the bottom of his windows. Somehow God let him see another day.



Tonight, I installed my Nuespeed strut bar from my beater, my Slipstreams, ITR wheel, and Mugen shift ****. I also fixed the timing, and the EGR valve. I know the wheels, and strut bar will add some weight, but the HF felt kinda scary in a few spots on the way back. The 13" tires just didn't feel stable at 80mph+ around certain turns. So a side project in addition to mileage I will be making it handle better as well. I should see some mileage improvements now, having fixed the engine problems.


I will log my next mileage after I get a full tank with the car fixed. I will be trying some new stuff in the future too. The cat will removed, and I will try a DX exhaust manifold, and see how that does. After that I will buy a header, and try it out. Then will be exhaust, and after that I have a D16Y8 intake manifold to try, and if it works out, a custom cold air intake will be fabbed, and tested. I have also heard that Federal Emissions ECUs are different, and provide more low end. Since the car was from Cali it has different maps for cleaner running. I will get my hands on one of those ECUs as well, and give it a try, and see what I get. After that I don't know what will be next, but I am sure more tests, and upgrades will be on the roster. I plan to add a VT wing, and some sort of lip, as well as lowering it, and adding a rear sway bar as well. It will probably get resprayed Championship White, after my KRX gets covered in that heavenly hue.

 

how much was the rust-free HF? my old crx dx got 40's mpg with a best of 47. I'm sure you'll get killer mileage.

HOWEVER, you know that adding things like a wing, lip, sway bar, etc is going to be counter productive in your gas mileage goals. but i can honestly say that i would do the same things...better handling and performance, with gas mileage as a bonus. good luck with it and i look forward to updates on your MPG! i hear gas will hit $4 soon...

btw, brians teddy bear rims have GOT to go! Lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zrickety &raquo;</TD></TR><TR><TD CLASS="quote">how much was the rust-free HF? my old crx dx got 40's mpg with a best of 47. I'm sure you'll get killer mileage.

HOWEVER, you know that adding things like a wing, lip, sway bar, etc is going to be counter productive in your gas mileage goals. but i can honestly say that i would do the same things...better handling and performance, with gas mileage as a bonus. good luck with it and i look forward to updates on your MPG! i hear gas will hit $4 soon...

btw, brians teddy bear rims have GOT to go! Lol</TD></TR></TABLE>

I paid $2500, Which may seem kinda high, but it was exactly what I wanted.

I actually feel that the lip would be productive in my quest for mileage. It in theory would block air from going underneeth, and causing turbulance. Also the wing is pretty small. I don't think it will matter. The sway bar, yes it will be weight, but sure it will help the car drive better. I also have this theory that banging around corners without breaking as much would be productive in saving mpgs. For you won't be slowing down as much, so you won't use as much gas to get going again. I will test both driving styles, and see what is better.

Yes the Teddies, are not my first choice. Brian is comfortable with his sexuality, and doesn't care what people think about his wheels. He likes them because they are hella rare. I am hoping he puts them on his Y49 he got for his GF. He has over a dozen sets of wheels, so who knows with that guy.

 

The teddy bear rims are so ballin

 

Bart is doing it again..........

 

makes me miss my first car... I'll always have a soft spot for polar white hf's

 

If you decide to get rid of the teddies I'll take em off you're hands.

Also i'm embarking on pretty much the same project. I need a good pizza delivery/driving 60 miles a day to school vehicle.

So good luck fellow traveler

 

Hopefully soon I'll be flying to LAX to pick me up a rust free crx, and bring it back to crxhell aka the midwest.

The only reason why I actually posted in this thread, is because of those teddy bear rims.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasfonzie &raquo;</TD></TR><TR><TD CLASS="quote">If you decide to get rid of the teddies I'll take em off you're hands.

Also i'm embarking on pretty much the same project. I need a good pizza delivery/driving 60 miles a day to school vehicle.

So good luck fellow traveler</TD></TR></TABLE>

The Teddies are not mine. That HF is my friend Brian's car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXBart &raquo;</TD></TR><TR><TD CLASS="quote">and after that I have a D16Y8 intake manifold to try</TD></TR></TABLE>

I see problems here. First and foremost, the HF has an EGR valve. But the D16Y8 doesn't. If you don't run an EGR valve, then you will get a code 12, which will send the ECU into open loop mode. The only way around this would be to use another ECU with HF maps. There is another possible problem with using this manifold. And that is airflow. Simply put, the runners on the D16Y8 manifold are MUCH bigger than the ports on the D15B6 head. And having that abrupt neck down at the head is probably going to hurt things more than help. So if you plan to keep the D15B6, stick with the stck manifold.

 

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

I see problems here. First and foremost, the HF has an EGR valve. But the D16Y8 doesn't. If you don't run an EGR valve, then you will get a code 12, which will send the ECU into open loop mode. The only way around this would be to use another ECU with HF maps. There is another possible problem with using this manifold. And that is airflow. Simply put, the runners on the D16Y8 manifold are MUCH bigger than the ports on the D15B6 head. And having that abrupt neck down at the head is probably going to hurt things more than help. So if you plan to keep the D15B6, stick with the stck manifold.</TD></TR></TABLE>


Yeah I planed on using a Si ECU. I might just eventually end up putting a VX motor in. Not sure yet. To early in the game.

 

Ah the open road. Seems like only yesterday Mike and I did our cross country fly out drive home with the Y.

Even funnier that you and I both were in the same garage on the same mission just different days and years.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX Toad &raquo;</TD></TR><TR><TD CLASS="quote">Ah the open road. Seems like only yesterday Mike and I did our cross country fly out drive home with the Y.

Even funnier that you and I both were in the same garage on the same mission just different days and years. </TD></TR></TABLE>

Yes, even funnier is the fact that both cars were a tooth off on the timing.

 

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

Yes, even funnier is the fact that both cars were a tooth off on the timing. </TD></TR></TABLE>

WHA!!!!!

I bet you found yours before you got to Ohio. I rocked straight through to NC a tooth off.

 

Nice find! good luck with the MPG!

I pumped 91 here in SoCal before my dyno appointment an it was $3.65!!!!!!!!!!

AAAAAHHHHHHHH!!!!

 

i got a really really good gas saving bin ill send it to ya if u want?if u dont have a chip burner ill throw it on a sst and send it out.i know it will pass all smogs test also.it might be the same program thats in the ecu u are looking for.how did the intr. look?

 

I think you might save some more mpg by switching to the dx transmission maybe. I had a crx with a dx motor converted over to mpfi with an hf tranny on it. I had to wait to shift at about 4k just so that when I shift into second I'll still be moving forward, and I would have to floor it once I hit second. If I were you I'd keep the stock intake as well.in an hf, you have to floor it up hills just to stay moving and an intake will kill your mpg if you're always flooring it. But maybe not with the 2 inch TB lol. Also, reducing the amount of air under the car will increase the downforce if I'm not mistaken, which will make the car require more energy to keep moving.someone correct me if I'm wrong. This is a very interesting thread by the way

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thevtecnician &raquo;</TD></TR><TR><TD CLASS="quote">I think you might save some more mpg by switching to the dx transmission maybe. I had a crx with a dx motor converted over to mpfi with an hf tranny on it. I had to wait to shift at about 4k just so that when I shift into second I'll still be moving forward, and I would have to floor it once I hit second.</TD></TR></TABLE>

Agreed. I don't know what Honda was thinking when they selected the gears for the HF transmission. But they seem to REALLY suck. On the low end, first gear is SO tall that it feels like a second gear start on virtually ANYTHING else. And the gap between first and second is HUGE- from 3.25:1 down to 1.65:1. Yet, third, forth, and fifth gears are spaced ridiculously close together. Honestly, the ONLY thing the HF transmission is good for is economy during freeway cruising.

Another option would be to use the HF fifth gear and final drive in a DX transmission. You would still have the sucky first gear. But at least you would eliminate that horrible 1-2 shift. And you would still have the low freeway revs.

 

http://www.gassavers.org

 

Nice pick-up, Bart. Now you're going to have to find another beater to save this one from experiencing the same fate as the hatch.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Its me DUB &raquo;</TD></TR><TR><TD CLASS="quote">Nice pick-up, Bart. Now you're going to have to find another beater to save this one from experiencing the same fate as the hatch. </TD></TR></TABLE>

From now until next winter I am DD this. In the winter time I will be DD either my Samurai once I get the 4.3 in it, or some other 4wd vehicle. I will still drive the HF, but I will be sheltered from the salt. That is if I am still in Ohio next winter.

 

An easy way to keep up the mileage is to check your tires often. There are reports that say 1-2% better fuel mileage just by maintaining your proper tire pressures. Also an air filter, a clean air filter is essential.

FOr the best mileage tires you will want something with a high mileage rating. think 130 000km rating. That will have much harder rubber and therefore less rolling resistance. Also most tires noadays have a 44psi max pressure rating. The higher you inflate your tires the less contact patch you have, which is less resistance on the road. Now this will negatively affect handling and you will wear down the centers of your tires prematurely, but you will get better fuel economy. Sticking with your 13s will help as well. Try a 155/80R13 tire size as well. Very narrow.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXBart &raquo;</TD></TR><TR><TD CLASS="quote">
From now until next winter I am DD this. In the winter time I will be DD either my Samurai once I get the 4.3 in it, or some other 4wd vehicle. I will still drive the HF, but I will be sheltered from the salt. That is if I am still in Ohio next winter. </TD></TR></TABLE>
Word. Your sammy is the ****.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g2_teg_ &raquo;</TD></TR><TR><TD CLASS="quote">http://www.gassavers.org</TD></TR></TABLE>



For motivation:
I once got 67.5mpg on an ALL HIGHWAY trip from Rockford, IL to Milwaukee, WI...
13" 155's RULE!

Now I have 14" 185's...Better Traction, but about 10-20% worse MPG

 

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


Yeah I planed on using a Si ECU. I might just eventually end up putting a VX motor in. Not sure yet. To early in the game. </TD></TR></TABLE>

If mileage is what you are after, I would not bother doing anything to the intake or engine management, as you are not going to improve on anything. Remember that a large manifold on a head with small ports is going to be a lose-lose situation. And EGR may actually have some fuel economy benefits by reducing throttling losses during part throttle operation. On the other hand, it probably would be worthwhile to at least try using a better exhaust manifold, as a close-coupled cat is beneficial for nothing other than startup emissions.

Of course, you should see better fuel economy with a D15Z1 swap.