So I've been calculating my MPG based on a 10 gallon tank, I've read some posts here and elsewhere where people's owners manual say a 10 gallon tank, yet the FSM says 11.9, so I was wondering which was correct. Also, I've read other threads where people are saying they are getting bad gas mileage, and are getting around 300 miles a tank, thats what about what I get now, whats the general consensus? Is this bad? If so, what can I do to improve? I'm aware alot is based on driving habits, and I don't accelerate rapidly off of every light or anything. Check tire pressure, I also recently: I changed my oil, fuel filter, spark plugs, spark plug wires.

 

It depends what trim hatch you have. My Si has a 11.9 gallon tank. I'm not sure the size of the DXs, could be 10 but I believe yours is a 11.9 as well.


You seem to have all the basic checks covered.

 

Reset your trip odometer every time you fill the tank. Before you reset the trip odometer, divide the mileage by the number of gallons you put in the tank. That will give you the most accurate fuel economy measurement within reason, and it won't matter how large the tank is.

 

11.9 U.S. gallons

Don't guess about your mileage. Calculate it precisely ---> miles driven/gallons used

 

Ok, so it is 11.9. Because I got 9.1 gallons earlier, and I've never had to fill it more than 10 even when it looks really empty. I fill it up full everytime, so assuming my last fill up was 11.9 and I used 9.1, I went 255 miles, so then I'm getting 28 MPG, I see alot of people consistently breaking 30 though.

 

Thats what I tend to do and I get between 28-32, 32 being my personal best, usually 29-30.

 

What percentage of those miles are highway cruising (roughly)?

 

Have you replaced the cap and rotor and then set the ignition timing to spec? What's your driving style?

 

I just noticed the car listed in your sig. If that's what you have and it's still stock, 28-32 mpg sounds pretty reasonable. When my hatch was stock, I got about that, and a little over half the miles were city driving. It has a slushbox though.

 

Mileage/gallons
look at your trip meter and when you fill up divide by the number of gallons you had to put in.
bad tune, worn parts etc could change your mileage to a degree

currently sitting around 27, with my driving style i'll live.

i remember reading the manual in my glove box and most models came with 11.9 but one of them had a 9.something tank

also it seems most of our gauges read empty with around 2 gallons left.

 

Most of its city stop and go. I don't drive on the freeway too much. I'm not really sure how to define my driving style, I don't race, or rev around alot or rev my motor really high. Just kinda drive, I realize thats vague, but its difficult to define, I drive the speed constantly, at most 5 over. I haven't changed the cap and rotor, but I will look into doing this. I have never timed a motor but I have a neighbor who can help me along with the FSM.

Edit: Its a DX manual hatch

 

I think with a complete tune up, you should consistently get 32 mpg or better from city driving with your car. Make sure to use the basic NGK spark plugs recommended in the owner's manual. Check the FAQs sticky for a diagram on setting the ignition timing.

 

Thanks (for the help all the time lol), I use the one that is recommended in the manual, is there anything else besides cap and rotor you think I should do?

 

Cap, rotor, and ignition timing. Then go from there.

Also be aware that the Honda distributor has about a 150K mile lifespan, so consider replacing it if yours has more miles.

 

I'm just past that about 157k

 

It's about time to replace the distributor. When you do, don't skimp on an aftermarket product -- buying an OEM distributor will give you another 150K trouble free miles.

 

i get 300-310 (95 EUR oct/93 US oct)to the tank on my 00' Si and that's with Autobahn Driving (HWY/80-98 mph).

BUT i run the Car empty until it starts to hesitate on the fuel (i keep a 2 Gallon gas can in the trunk at all times)

keeping off the VTEC "Most of the time" but some spirited driving.

-Mods
.AEM V2 CAI
.NGK Spark plug wires
.NGK IX Iridium BKR6EIX-11
.Skunk 2 Full Exhaust.

I know octane rating plays a factor as well because I've switched between 89oct, 91oct(E10), and 93oct.

Of course 93oct gave me the best
91oct(E10) which is Europes newest version of "Biofuel" and the Honda ran like pure @$$.

 

www.fueleconomy.gov is a good tool for comparing one's Honda's MPG with what others are getting. Note that there is a government value (based on lab testing) and also anecdotal reports from individuals available for almost every make and model.

A stock 95 DX hatch, manual tranny, tires inflated per spec should get 29/36 city/highway MPG per the government lab tests. Nine individuals reported; their average is about 39 mpg. It looks like the nine individuals' mpgs are top heavy with highway driving.

Overinflating tires by 5 psi or so will make a difference in MPG. But know the risks of overinflating, namely increased tire wear in the middle; harsher ride; other small effects. Else tuneups like the others said are key. I think the PCV valve and O2 sensor should be replaced about every 100k miles. Use only an OEM PCV valve. Use a denso or NTK oxygen sensor. Here are the other tips I have used for my Hondas to get the best gas mileage: http://sites.google.com/site/hondali...gasmileagetips

As others also pointed out, use either the trip odometer or regular odometer and measure actual miles and gallons used to top off, one click on the pump. Do not overfill, since this risks getting gas into the fuel evap system's charcoal canister.

 

This is a reliable way to kill the fuel pump.

 

I get 330-340 on my EM1
But since I'm having an ac on thesedays my mileage dropped to around 300

 

CX and VX have a 9.9 gallon tank. DX and Si should both be 11.9.

I found a 13.5 gallon aftermarket fuel tank made by Spectra (got it in AdvanceAuto's website with a killer coupon for 100 shipped, they have great online deals) that bolted right in place, so I don't have to stop and put gas so often.

To get better mileage, besides the helpful advice you've gotten in this thread, I recommend changing your fuel filter and having your injectors serviced by Rich over at Cruzinperformance.com. I've had many sets of injectors done by him and everytime I noticed a tangible improvement in efficiency and an overall smoother engine.

http://cruzinperformance.com/injsteps.html

Good luck,

-Walter