EKphil123

Hey guys, i have been searching for fuel consumption guides but have had no luck..... I have a 96 cx hatch with the d16y7 and i am getting crap for kms from a full tank, i have done cap and rotor, plugs, wires, top 02 sensor, i have the bottom but havent put the bottom in as its not throwing a code, and fuel filter and all i seem to get at max is 350km per tank..... i have a friend who "claims" to get 550-600 per tank, driving style is old man i go 5th gear through town lol, any help would be greatly appreciated, thanks

Phil

grumblemarc

iTrader: (4)

You realize this is a 17 year old car you're talking about?

EKphil123

yes i do, but it has only 134,000 kilometers so its been barely driven....

94EG8

Km per tank is a horribly inaccurate measure of fuel consumption. And extremely useless unless comparing 2 of the same vehicle.

That said I used to get 650 - 670kms to a tank with my '94 sedan when I had a long geared DX tranny in it. I was getting 48 - 51 MPG (imperial gallons) and it didn't matter how I drove it.

goldsy

350kms to a tank is definitely low. I drive a 97 CX hatch and I get about 550 to a tank all highway driving and about 500 with all city driving. Mine has 280000kms on it and a bad secondary 02 sensor.

canadaek

How many liters does it take to fill you car ? I thought I was geting 450km to a tank but I only ever put in 33-35 l the tank is 45l so my gauge says its empty but thete is still 10+l i'm going to check the float when I find time.

B_Swapped93

agree how many liters does you'r tank take,next are you'r plugs black(running rich) my 99 dx gets about 400-430 with in town semi-agressive driving.

goldsy

45L tank for me. When my needle hits E it usually takes 36-38L to fill it.

B_Swapped93

now we just need to know OPs L consumption when he fills up. depends if you drive it till that little light comes on to. i do lots of city driving so i always do, worst case im walking to a gas station.

hyperforming

I get around 560 + kilometers a tank average. I have a 99 dx 5 speed, this is with power steering but not using the ac. I had to do the conversion because I'm in the US and its around 350+ miles for a full tank

goldsy

The CX doesn't have a low fuel light...... Mine doesn't anyway.

hyperforming

oh and i have 221,000 miles on the Odometer

B_Swapped93

is that in town/city ? 221,xxx miles adds to about 410,000 KM's afaik

rovafa2002

Hi EKphil123,

Make sure that...
1- You have the correct spark plugs for this car
2- You are using good gas and not regular one (these engines are too compresed)
3- YOUR TIMMING IS CORRECT (this is critical on fuel consumption, mine a 99 EX has 12 +-2 BTC so I put it in 14 btc which is better for economy but will hurt a bit top end power at higher rpms) Check with is the correct one for your engine.
4- You chance the rear 02 sensor too (it might not throw a code but with years these sensors get slower to sense 02 variations hurting fuel economy)
5- Clean yout throttle body with Carb cleaner
6- Clean IACV with carb cleaner
7- Clean IAT sensor with electronics cleaner
8- Clean MAP sensor electronics cleaner
10- You are using a thermostat and your engine temp gets to correct operating temperature fast (if it doesnt ECT sensor will force the ECU to run on rich mode eating gas)
11- Change your air filter if you didnt
12- Check your tire pressure, personally I use 31 psi in all 4 tires, since here its a bit bumpy but if you dont have no bumps on your road you can go to 35psi easily
13- If you have a manual transmision one DO NOT PUT YOUR CAN IN NEUTRAL WHILE COASTING. There you are wasting gas to keep the engine running. Leave it in gear until 1200 rpm since it will not be using ANY gas. When it gets to arround 1200 engine will kick in again you will sense that since the engine braking stops.
14- Check draging of your car, you can ask a friend with a newer car to let it coast down hill to see if yours is dragging or not.
15- Do not use your AC to measure new consumption
16- Do a seafoam treatment in your car (its pretty easy, lots of videos on youtube and tutorials in this forum)

I cannot think of any other to help you but I guarantee you that following those you will get some better numbers.


Good luck!

kyden

^^

87 is recommended on a d16y7.
rear o2 sensor does not affect fuel economy.

I would make sure your engine is going into closed loop. (any scan tool would show you this)

what are you getting for mileage per liter?

hyperforming

more highway with decent amount of stop and go traffic

fleabag

Good post but I can think of a few more OP can do...

1. Get the schematic of the electrical grounds in the engine bay and clean up every single one of those grounds. Scrub the bolt's threads, under the head, the top and bottom of the washers, the eyelits on the wires, (don't scrape paint!), scrub everything until they're nice and shiny. There are quite a few electrical grounds in the engine bay. Cleaning up electrical grounds, especially on an older car can make a huge difference though it does take time. One reason why you want to clean your grounds is that with higher resistance, your alternator has to work harder (more gas) and your o2 sensor signal becomes weaker (lower voltage) which tells the car a lean condition, therefore it dumps more fuel. (0V=lean, 1.25=Rich, computer responds accordingly)
2. do a valve lash adjustment....

Telecatster

If you are basing your mileage on a full tank to empty divided by your odometer reading it will not give you an accurate reading. The older civics gas tank is a poorly baffled slosh pit and wouldn't surprise me if you could drive your gas tank well pass the white empty line on the fuel gauge.