I have a 100+ mile commute everyday to work. It is mostly interstate travel. It is a 4 cylinder* dx, automatic, 4-door, runs good.

*rhn2-2vjgffa is this a f22b1 or f22b2 (it doesn't say vtec on the valve cover, just 16 valve so that's a f22b2, correct?)

Evaluate the following for performance/economy

a)Larger wheels/tires
b)Header
c)Cat bypass/high flo cat and upgrade pipe/muffler
d)Cold air intake/kn filter
e)aero effects

What kind of mpg's should I expect stock vs.these changes.

Thanks for letting me be dumb!!

 

You can expect the following:
a) Virtually no gain (but you will induce speedometer and odometer error).
b) No gain and potentially a loss (back pressure can actually help fuel economy at highway speeds)
c) Same answer as "b"
d) No gain and potentially a loss (cold air is actually the enemy of fuel economy as it hurts fuel atomization)
e) If the aero effects successfully reduce the drag, then you may see something less than a mile per gallon improvement; that said, the money you spend on the aero effects will probably take years to offset in fuel savings, and that's assuming you don't damage the add-ons on such things as curb stones and have to pay for repairs.

Long story short, leave your car alone, keep your foot steady and out of the power zones, and save your money.

 

I keep car stock, but you can gain a minor amount on mpg by putting in 2-3 psi above recommended tire pressures.
I do that and it doesn't seem to cause any uneven wear on tires.

 

Thanks shipo and UhOh!

 

I would leave your car stock. Modifications will cause you headaches later on, plus you won't get much out of them.

For maintenance, you may want to clean the caliper slide pins and use silicone paste to lubricate them. Clean the EGR ports. Clean both sides of the throttle plate and the throttle bore.

What kind of gas mileage are you getting with your car right now?

 

Do a standard tune up, run sea foam I. The gas and into the intake, replace plugs, distributor, wires air filter ect. Your car will thank you for that.

Your accord should be getting around 25-30mpg

 

I agree with the others, mods won't gain you much if any. Just perform recommended maintenance including what Silver6gen said and change the fuel filter.