raphael

Gentlemen, I've been reading about average miles per tank people get with their civic si's and I was am concerned. I've been reading. with regular city driving people get about 200-250 mpt. I get 180. Even the highway I don't get more than 210. My car is completely stock. Anyone have any say about this?

My car is a 2008 Honda Civic SI sedan. And no I rarely go into vtec as I don't care to abuse my car.

TunerN00b

Absolutely.

Miles per tank is a meaningless measurement. Some people run the tank dry, others fill long before it is actually empty, and the gas gauge is very inaccurate.

Use miles per gallon, which is a meaningful measurement.

If you're still getting worse than expected, verify that the car is in proper running shape, especially alignment and tire pressures.

If it is, and you're still getting poor mileage, than you probably need to learn how to drive correctly. This isn't an insult to you, this is an observation of the vast majority.

tlarimer

iTrader: (3)

How many miles are on it? Are you using premium grade fuel? Using the same brand of fuel, etc?

raphael

I'm certainly not the problem. With my 99 em1 I never had this issue. Btw I as say Miller's per tank because I'm saying from empty to full.

raphael

47k. Second owner. Different brand fuels, always premium.

tlarimer

iTrader: (3)

I just picked up an 07 FA5 and so far I have 160 miles on a little less than half tank. Something is definitely off, Filters, PCV all replaced at scheduled intervals? It may be worth the effort to reset and perform ecu relearn procedure.

TunerN00b

Still completely meaningless.

Define "empty" and "full", because everyone has a different interpretation of them. My car still has 2.5 gallons in the tank when the needle hits E, and slightly over a gallon when the light comes on (1/8 past E on the gauge). I've also filled 12.5 gallons into a "12 gallon" tank, because the filler neck holds fuel too.

Jonathan_ED3

I couldn't agree with you more. I hate when people talk about how many miles they get "per tank".

It's absolutely, 100% utterly retarded and meaningless.

People, do some actual MATH and calculate your MPG. And don't rely on the MID displayed on your speedo/odometer like a lot of these new cars.

The MPG MID on my TSX routinely reads 6-10% too high.

TunerN00b

Some ignore (at least some of the) gas burned while idling at a stop, and others ignore the cold enrichment.

The gauge is to help the driver adjust his driving habits, not provide an accurate measurement of reality.

Jonathan_ED3

I understand that.

However, most people don't and actually take it as face value as a true representation of their MPG for any given tank.

And most people I've ever met don't even reset the trip meter or have any idea WTF it's even useful for.

tlarimer

iTrader: (3)

OP, to provide you with some perspective, my bone stock 07 Si sedan got 29.23 mpg overall average on the roadtrip we just did, 1163.8 miles, using a total of 39.218 gallons of fuel at and average speed of 77.4 mph, so yes there is something going on with your car. How much fuel are you putting in when your gauge reads empty?

CCoady26

Next time you fill up reset your trip. At the next fill up divide the gallons you put in by the milage from your last fill up. That'll be the easiest way to figure out MPG.

hiphopsi

180miles per tank???? do you get stuck in traffic? are your tires inflated? since you dont hit vtec do you drive at 3k rpm?????

hutzman

everyone who says miles per tank should be rounded up and put in a gas chamber. the guy that got 29.2 MPG on a road trip is actually a little low. he should have gotten at least 32 MPG. I'd always check the tire pressures, air filter, and clean the MAF sensor if I'm having mileage issues.

0Group1AutoParts

When I had my '08 Si Coupe, I would average 26-27 mpg (calculated using the trip meter and how many gallons I'd fill up with) with mostly city driving with the occasional vtec fun.
Does the car feel like it's driving as it should? Power wise?
As others have stated, you may want to check your filter, MAF.

dyee

I haven't read the above, but here is my take:

I got my car at 36900 km (~22,900 miles). It is now sitting at 43k km (~27,000 miles).

The ECU was never reflashed after the original owner removed the header/catback for the stock one. At first, I was only getting around 360km (223 miles) per tank, but now I am getting around 400km (250 miles) per tank. I drive like a grandma a lot of the time, but every tank, I will push my car once or twice only. Gas is expensive here (1.50/liter or $5.68/gallon).. though no where close to Hong Kong or the UK.

- My car has a stage 1 CT-e supercharger and CAI. Everything else is stock.
- I mostly drive in the city (95%)
- I fill up until my nozzle stops, and I add around 0.5L after that. I fill with Octane 91 all of the time.
- When calculating my mileage per tank, I start from a full tank to the very moment the gas light comes on.

flaco2007

i know this is an old thread. but i have the same issue, i drive an 06 si. work 50 miles away form home round trip is 100 miles exact. about 90 miles are highway the other 10 is city. i uses i 1/4 tank of fuel per 100 miles. dealer saids iff ther is no checkengine light on they cant diagnose. has anyone had this problem solved?

JAA11Si

Have you calculated actual MPG? I pull an average of 32.6 MPG doing the same type of driving as you. (35.9 MPG if 100% highway, like a road trip out of state somewhere.) Miles per tank? Arbitrary number that's impossible to duplicate. MPT is nothing more than a nice indicator of approximately how you're doing with this tank of gas, nothing more. Def not an accurate way to measure real gas mileage.

To the OP I ask the same question: have you calculated actual MPG? It's not hard. And if you truly cannot do the math, use Fuelly[dot]com and it will do the lifting for you.

fergy016

I would look at your maintenance schedule in your vehicle manual,
make sure to keep an eye on items listed for fuel efficiency:
fuel filter
spark plugs, either change or check the gap per vehicle specifications.
air filter (replace when dirty)
(map) sensor in air tube is clean
distributor cap/rotor (changed every 30k miles I think, check maintenance schedule)

and if still down on power might be a worn out catalytic converter which happens after 8 years usually. They are warrantied from dealership for 8 years most of the time btw.

mattdexter

depending on what grade of gas u use and how u maintain it means everything


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Bror Jace

Again, for everyone: When trying to diagnose a fuel economy problem you need to calculate your fuel economy more precisely and not talk about "XX miles on about 1/3 of a tank of fuel."

For those who can't figure it out (it's not hard):

Step 1) Fill your tank. Reset trip counter to 0
Step 2) Drive ... at least half a tank
Step 3) Fill up again. Divide the miles by the number of gallons on your receipt
Step 4) Write this down and repeat several times to show a trend. You will see large variation between tanks as fill-up is not precise.

Trying to describe where your needle is on the gauge in relation to about how many miles you've traveled is a fool's errand. Don't waste everyone's time with that.

Your mileage suddenly drops off precipitously? Check your brakes for a sticking caliper or any other thing that would cause your brakes to be on all the time.

DaveSi677

so many factors play in to getting better gas mileage. Tires, suspension, mechanical, aero, fuel type.. the list goes on!

I would recommend doing a overall tune up and from there start calculation MPG instead of how many miles you get per tank!

duckmanEG

Only issue I see with this old thread is this guy is abusing his Si by not going into VTEC. The engine was designed for the Rpms. It is not abuse. I go into VTEC every single day. I probably even VTEC every time I get up to speed. I redline the car pretty much every day. Bought my car at 100,000. Have 160,000 and I haven't touch a thing besides oil.

DaveSi677

I do agree it's important to stretch it's legs every now and then!

bairdandrew77

If your car still has low miles I'll take the problem off your hands