CRX VX Mileage Experiments
 

All tests were complete loops starting and ending at the same gas station and the same pump. The fill included fuel viewed at the flapper door. At each fill I waited until all air bubbles dissipated (including rocking the car). Every trip was real world driving. All conditions and all speed limits were duplicated. There were no one-way long downhill runs. If we went down, we came back up the hill. The seven trips averaged 398.589 miles each, for a total of 2,790.124 miles. Tire air pressure is 40 psi front, and 32 psi rear.

The wet weight of the original HF was 1,780 lbs with a 10 gal gas tank; its best on a 417.3 mile trip was 51.7 mpg, no luggage, no tools, but it regularly averaged 42 mpg and had to use premium gas to nullify the pinging.

The wet weight of the CRX HF/VX/CX is 1,833 lbs with a 12 gal gas tank. The as tested weight, including two adults, two dogs, tools, drinks, food for all, jackets, blankets and pillows (for dogs). Who said a CRX only fits two? The total as tested weight 2,441 lbs, wet. And, it runs on regular.

The L02 four-wire ECU was used during the first four trips. The lowest mileage recorded was 48.2 mpg. The highest mileage was 51.452 mpg. This was for a total of 1,446.294 miles.

The L00 CA five-wire had only one test. It showed 49.597 mpg for 417.1 miles driven. This trip was identical to one of the trips using the L02 ECU.
(The L02 previous trip was 49.63 mpg at 417.4 miles.) Additional tests with this ECU did not seem warranted. The total non-lean burn average for the L02 and the L00 was 49.544 mpg.

The A00 lean-burn five-wire has had two tests, to date. The first: 408.62 miles traveled, produced 55.477 mpg. The second: 509.49 miles traveled, produced 58.455 mpg. At that mileage the 12 gal tank will travel 701.46 miles. It is an awsome feeling to travel 350 miles and only use a half-tank of gas. The average lean-burn capable A00 mileage increase (7.422 mpg) over the L00 and L02 non lean-burn ECUs is 14.98%.

The vehicle has not been altered from its original exterior excepting deterioration of the 23+ year-old plastic front end. It's missing a tooth and one eyebrow that blew off during the first road trip. (Plastic cracks in the sun, don'cha know? This car was from Southern California.)

In the future it will have aerodynamic modifications (and repairs :D).

I still am shooting for a 70 mpg average (just 13 mpg to go :thumbup: ).

Nice!!!!!!!

Very cool and thanks for sharing. I'm going to do this swap just need to find a clean CRX w/o rust.

Cool! Hope you find the CRX you're looking for soon. Are you looking for a 1st gen or 2nd gen? I'll keep my eye open if you let me know which one. I run across them from time to time. 1st gen is a lighter car, 2nd gen more plug and play (though not entirely). What state do you live in? I'm in CA not much rust out here. Recently I found an '86 Si, factory black with moon-roof, at a local pic-n-pull for sale as a whole car. It had been hit in the left front corner (looked like all cosmetic damage). I didn't look very hard at it since I wasn't in the market. They were asking $999. Just something I saw recently. Anyway, the best of luck on your project.

I think I want a 2nd gen. I'm from Minnesota but will pick a clean CRX up anywhere. Everything around here is completely rusted out. Thanks a lot!

It's a real pleasure to hear the real world results of your brave experiment! I can't wait to see what you do for aero-mods!

what's the A00 lean-burn five-wire ecu?

This is the first version of the P07 computer used in the Civic VX model. The Civic VX uses a 5 wire o2 sensor to monitor the lean burn and works in conjunction with the P07 A00 computer.