Integra bad gas mileage

[WadeTustian]

So I've only been getting 250ish km per tank and people say I should get 450+ I'm only getting 11.5 mpg any help

[Neckbeard]

hows your oil doin? tires inflated correctly? are you carrying a huge load of somethin? O.o

[WadeTustian]

Empty sub box in the back but this was all before that, just changed oil and spark plugs tires are new and holding air!

[Neckbeard]

is your engine making any funny noise?

[ALAMO695]

try seafoam, carbon buildup cleaner

[Guest]

have you replaced the o2 sensors?

[WadeTustian]

Engine seems fine although when I rev and rpms drop they stop for a second a couple hundred about normal then continue to drop back down to that number, I did seafoam via gas tank and spray in intake so we will see how that works

[WadeTustian]

have you replaced the o2 sensors?

No I haven't but might have too

[Skullz]

o2 sensors

EGR stuck closed or open

[ModestDb]

So I've only been getting 250ish km per tank and people say I should get 450+ I'm only getting 11.5 mpg any help

So many aspects of a vehicle can effect fuel mileage. A few preliminary checks are in order as well as further info such as year of your model and what engine if there are any varying sizes for your year/make/model.

Do you have a check engine light on?

Is your air filter clean?

Is your tire pressure evenly matched at no less than 32 no more than 36 psi?

Do you have any exhaust leaks?

Have you had a tune up (plugs, wires/coil boots, distributor cap and rotor button, pcv valve if that vehicle is equipped with them)?

Have you changed your fuel filter?

Have you changed where you fuel up at?

Have you tried any types of fuel treatment from a parts store?

Have you changed your oil?

What weight oil do you use in your engine? Synthetic or not?

Have you ever had a compression test done? A compression leak off test?

Under your hood do you see any noticeable sensor harness' unplugged or broken?

Do you see any vacuum lines broken, or hear any hissing while the engine is idling?

Do you see any igniton/spark plug wires touching exhaust or anything hot that could compromise their insulation? Possibly rubbing something from engine vibration?

Have you checked your brakes to verify you don't have a caliper or caliper slide pin sticking and/or over adjusted rear brake shoe/e-brake?

Does your engine coolant temperature gauge read low? Not read at all?

Answer those and/or verify and I will be more than happy to lend a hand to get you back in the realm of mileage you should expect from an Integra.