I know this issue has been chewed in the past.

I am driving 05' I-4 accord EX. One sunny day, about two years ago, I had a significant drop in MPG. I drive mainly on highways (in MA), about 15 miles each way to work and 15 back, the rest is normal family drive...evenings, weekends etc. The drop was from around 28 (average) to 23-24. It happened just like that. I didn't change anything in my driving habits, I use the same road, same gas stations, same speeds (between 70 and 80).
I changed the air filter, it did nothing. I made sure I use the same gas station (I normally use 2-3 stations) for about three weeks - no change. I thought it's the winter.
10 days ago I decided to make a small experiment and sacrifice some speed. I filled up and drove with cruise control at 65 mph until the yellow/orange light came on. The result is 27 mpg.

So, my questions to you:
Those who get 28-32 mpg - what speeds are you driving? I read in this forum someone who is having 32 at 75 mph, so with my 65 mph I should have gotten a much better result than 27.
Second question - does anyone else get the same result as I am in the MA area?

Last - since this was a leased car and I just purchased it, and I had no intention to purchase the car when I initially leased it, only maintenance I did was following schedule A of the owners manual/Service Required lamp. The air filter that I changed is not part of that.
Is there anything else I could do to improve mpg? Is there any part that may have gone bad (like a sensor or something) that does not cause the Service Required light to go off?
I do check tire pressure regularly, so it's not the tires. The car has 41K miles. I am pretty sure it should do better than 27 on the highway.

Perhaps I should switch to a different gas station...?! Do gas stations/companies use different fuel to an extent of such an impact on a car?

Thanks in advance.

2007 EX-L K24 manual sedan for a commuter car. As I have long 85% freeways commute in Houston of 50 miles each way, 87 octane E10 (Everywhere in Houston year round) my FE numbers are:

75-80Mph 30.5Mpg
70-75Mph 32.5Mpg
62-65Mph 36.5Mpg

All these numbers are with A/C (I’m in Houston) and are consistently repeatable.

Try a different brand. Mine runs lousy and mileage drops when using Shamrock gas. Other brands, so far, are just fine.

Have your brakes checked to see if they're sticking. Something had to change on the car for that big of a drop.

On my V6 I easily get 27MPG to 28MPG running 80MPH on the highway with the AC on in hot & humid conditions. When I made long trips in cold weather (below 40) I was getting between 29MPG and 32MPG, always 75+ MPH.

you might want to have the ebrake checked, mine was dragging after it got nicked and was hanging up. Gained 3mpg up fix.

When the car was still under a lease, and under warranty, I called the shop at my dealer and they that said since the Check Engine doesn't come on they won't be able to tell if anything wrong, and the only solution they had is for me to let one of the mechanics drive the car at night for around 100 mph in highway condition :thumbsdow. Of course I refused to do that...not even a tiny chance I would let anyone "test" my car like that just to hear the next morning "um, sorry, the car seems perfect, we didn't find anything"...not to mention the mileage on the car (lease, remember?), and not to mention what else these guys would have done with it that falls under "it doesn't hurt if you can't see it" :paranoid:...just the thought of that gives me the shivers...

Parking brake check is easy.

Pull it up slowly, listen to each click until it gets to the point where you have to pull excessively hard to move it up anymore.

It should be 6-8 clicks. If not, we'll find some adjustment info for you. It's not terribly difficult. Hardest part is getting to it, which a simple screwdriver can do. :yes:

If the tires have lost a good deal of tread that can also be a factor. :yes: Also, are all the tires the same brand? OR if you changed the tires, and didn't use what was on there before, that can explain the added gas consumption too.

If you've never had the transmission serviced, I recommend that you get the fluid changed at your next oil change, assuming you use a dealer, as only Honda fluid should be used; no flushes, just drain and refills.

How often are you getting the oil/filter changed? What brand of gas is the station you say you consistently use, I used an off brand station for the longest time, then I switched to chevron and it looks like I'm getting an extra 20 miles each tankful.

Report back!

Parking brake check is easy.

Pull it up slowly, listen to each click until it gets to the point where you have to pull excessively hard to move it up anymore.

It should be 6-8 clicks. If not, we'll find some adjustment info for you. It's not terribly difficult. Hardest part is getting to it, which a simple screwdriver can do. :yes:

OK, not quite sure I understand what I am looking for. Basically, if I get 6-8 clicks does that mean that mean that it is not locked?

If the tires have lost a good deal of tread that can also be a factor. :yes: Also, are all the tires the same brand? OR if you changed the tires, and didn't use what was on there before, that can explain the added gas consumption too.

I still use the original tires (41K miles and about 3.5 years). Obviously they lost some tread...I always knew that proper inflation is an issue, had no idea that tread (or the lack of it) can have such an impact. Again, the drop was noticed in a very short time...I'd say two-three weeks.

If you've never had the transmission serviced, I recommend that you get the fluid changed at your next oil change, assuming you use a dealer, as only Honda fluid should be used; no flushes, just drain and refills.

Never changed transmission fluid, I will take care of that.

How often are you getting the oil/filter changed? What brand of gas is the station you say you consistently use, I used an off brand station for the longest time, then I switched to chevron and it looks like I'm getting an extra 20 miles each tankful.

I have been following the manual (schedule A), which is consistent with the Service Engine Soon light - every 10K. As I mentioned, this was a leased car and I had no intentions of buying it. Now that I own it I'll follow a shorter intervals between changed.
As to fuel - I suspect that the it has something to do with the problem. I fill up 98% of the time at Hess (not sure if it is all over the country)...they are cheaper than Exxon and other large companies. Maybe that's the problem...?! Lower quality gas?