Civic guy with goal of 50 mpg
 

Hello all!

I drive a 2006 Honda Civic LX. I've owned it since new and thought it was the ugliest thing ever. Sat inside and thought this is a pretty fugly interior as well. But I bought it anyway because it had an mp3 CD player stock (ubiquitous now but in 06, it was one of the first) and the sticker said 40 mpg. The only other car that handled better in its class was a Mazda 3 which had very depressing FE. Double win, high FE and fun to drive.

I currently drive 106 miles roundtrip to work with over 90% freeway. I used to drive in the middle lane keeping up with traffic and I averaged 40 mpg hypermiling. I got tired of the honks behind me and moved over to the slow lane and mpg surged to 43 mpg average. Last fill up was 46 mpg but I think that's because the summer blend has kicked in.

My goal is to get 50 mpg so that I only need to fill up once a week. I can already do this but it would be a nail biter on Fridays and I don't like the taste of my nails. The car is stock and I am not sure what I want to with it yet to get to my goal. I do know what I don't want to do.

I can't P&G because I am in an urban area or maybe I'm already doing it in stop and go rush hour traffic. I once made it the entire 90% length of my commute on the highway not touching the brakes in rush hour traffic. I don't want to make a grill block because I am deathly afraid of overheating the engine in hot hot CA weather. My first two cars as a teenager overheated on a daily basis.

Basically, that leaves hypermiling. I already practice DWB, DWL, coast on neutral, and engine off at the few lights I encounter. My average speed is a little under 50 mph which is the FE sweet spot for my car. Sadly, I don't choose this average speed, that's as fast as I can go in traffic-choked Bay Area, CA.

Other two options that I am hesitant on is a scangauge and pump up the tires. Scanguage is quite expensive and I am skeptical that it will help me besides telling me I am using too much gas. Well, I wouldn't be using too much gas here if I didn't want to go faster so I would've done the same thing with or without the scanguage. I can see where my thinking is flawed so please don't flame me too hard. That's why I am still mulling over purchasing one. Pumping up tires causes uneven wear and means I would have replace the tire sooner. This would negate the cost savings I get on FE. Not to mention lowering my traction and increasing my stopping distance is a safety risk.

Im telling you that the Scangauge is the single best thing ive done. I felt like you, that it was too expensive, i was doing well. My 09 Honda fit went from 38-39 mpg to 42. I've seen bursts of over 52mpg on trips. It shows you were exactly the sweet spots are. Especially during DWL. Because you can see what engine LOD is most efficient. What speeds net better mpg, what shift points. And something i've learned that i didn't even realize before was I can't tell very well if I'm on a mild uphill or downhill. The can tell instantly on the Scangauge. And I know when to push harder or back off. And as far as overheating that civic. I seriously doubt it. Even in CA. I blocked the entire front of my Fit off and the temps stayed beautifully. However with the scanguage as well you can monitor it the whole time. If you only made one decision, I would recommend getting something to monitor your car with.

I completely agree about the Scangauge. He ^ said most of what I would say, but it's the single best thing I've done for my mileage. All the driving tricks will kick up a notch or two when you have instant feedback.

Tires - I'm at 53,000 miles on my tires, inflated "well above" spec for the whole time. I need to replace them soon as they're worn down to the indicator bars. Evenly worn all the way across.

I haven't found any loss of traction either , and I have places on my commute where I test that fact daily.

You didn't mention any kind of aerodynamic changes. Look at the wheels and wheel wells, the front end, etc. You could probably close half your grille and still have plenty of cooling. If you get a Scangauge you can know this for sure.

The ScanGauge also stores your maximum coolant temperature encountered in the current drive - perfect for putting your mind at ease if working on a partial grille block. (Though you still need to listen or wire an LED to know when your electric cooling fan is coming on - since you don't want it running much to compensate for an overly-aggressive block.)

Also, there are less expensive options than the full SG2 - ScanGauge E, UltraGauge, etc.

Pale is spot on with advice on looking at more aerodynamic modifications, since you spend the majority of your driving on the highway.

PS - welcome to the forum!

As far as the tires go, I wouldn't hesitate to pump them up. Go to any autocross and ask people what pressures they're running--you'll be hard pressed to find anyone running as low as the vehicle manufacturer's specification because inflating the tire beyond that helps keep the tire from rolling over onto the sidewall in cornering and reduces scrub on the tread.

I have an 05, one year earlier than yours, and have the both grills blocked except for a 1"x12" horizontal slot to let air into the lower opening. We've been up to 91 here in the Midwest already with no observed effect on engine temperature. Try a temporary block first, and if you have cooling issues open it up a bit until you find the right size.

The ScanGauge monitors temperature? That I did not know. I'm just a numbers kind of guy and the cost has to make sense. My current mindset in making 46 mpg means I've nearly maxed the potential of my vehicle with driving techniques, that any additional gains due to throttle input would be minute. Significant gains would need to come through modding.

Thanks for all the comments. I'm gonna start with increasing the tire pressure gradually and see where it gets me. The ScanGauge will be next if a few more comments kick me in the same direction.

the scan gauge monitors : intake temp, coolant temp, engine load, map sensor, open or closed loop, throttle position, rpm, speed, voltage, distance traveled, and gas consumption and many different ways. as in cost per minute, average tank commute, average mpg on tank, instantaneous mpg. There is also a function to design your on meters but I havent messed with that other than to display an average mpg over trip or tank. Cant remember what was stock. Im sure im missing a couple, and it checks and clears engine codes. Which has come in handy on several occasions.

There is alot of inexpensive mods to be done to help aero and mpg. If you havent checked out the tips and efficiency mods at the top they'll get you on the right track. My front air dam cost me about 10$ to make out of lawn edging and ill be putting on side skirts for probably around another 10$. And they wont stand out to bad either. Good luck modding. Im trying to stick the 50mpg mark as well. Ive got it at 55mph. Now im trying to aero mod to maintain 60mph and still get 50mpg. People near me are normally 70 on highways, in the slow lane.

I keep thinking that, but 5 years later I'm still finding incremental improvements.

I too would recommend investing in a Scangauge or similar instrumentation hardware. Having instantaneous fuel economy feedback is invaluable, especially for testing mods. I have mine set to intake temp, coolant temp, instant MPG and trip average MPG, but there are a lot of other options to choose from as well.

As for aero mods, the front grill block is probably the easiest mod to perform. Other big-gain mods you can try are wheel skirts (start with rear wheels as those are typically easier to skirt) and an underbelly pan. If you add those, you should have no trouble getting 50 mpg and above.