Vaguely inspired by the episode of Top Gear I just watched (on netflix) where they drive from Switzerland to the middle of England on one tank of gas, I've started wondering if i can get better gas mileage from my Civic.
It's a bit of an interesting situation though. It's an 89 Civic wagon with a B18A1. I drive 20 miles every day, the majority of them highway at about 3am, so no drafting. Two to four days a week, i drive an extra four miles delivering newspapers. So that's four miles over the course of 1-2 hours with constant starts and stops. I did remove the passenger and back seats so i could cram all the papers in it. As it sits, I average between 25-29mpg. I have yet to break the 30mpg mark. My personal best is 29.4.
So what can i do, that costs little to no money, to improve fuel economy. I realize that most of the difference will be in how it's driven. Since it lacks a muffler and I'm out bright and early I don't ever drive it too hard. Tire pressures are kept around 37psi.
The body on the car is trashed, so i'm not opposed to doing any modifications in that department. Would covers over the rear wheels do anything for me? Upping the tire pressure even more? Are there optimal shift points (i usually shift around 3500rpms)? Does it help to be in 5th at 25mph or am i actually hurting things? Am i just being crazy?
Jacques
BTW, IIRC the cars in that episode were diesels...
Any aero mods will only come into play if you're doing sustained high speeds.
I'd think the newspaper delivery isn't helping with the gas mileage, but short of taking a bicycle there isn't much you can do about that.
I assume you're keeping the drive train well maintained and it's had a recent tune up?
BoxheadTim wrote:
BTW, IIRC the cars in that episode were diesels...
Any aero mods will only come into play if you're doing sustained high speeds.
I'd think the newspaper delivery isn't helping with the gas mileage, but short of taking a bicycle there isn't much you can do about that.
I assume you're keeping the drive train well maintained and it's had a recent tune up?
I think only the Subaru was a diesel. Either way, i've owned cars that get 40+MPG so 25 makes me sad.
I was thinking the aero stuff for the highway trip. I only deliver in the car thursdays, sundays, rainy days, and if i'm running super late. All other days i have a tricycle I use. Keeps me in shape and saves gas.
I suppose i should probably start with a tune-up. Sad to say the car's been a bit neglected.
thanks!
Jacques
On the highway stints go as slow as you can stand in 5th.
If you're averaging almost 30mpg with the highway driving plus 1-2 hours of stop-idle-go-stop-idle-go I'd say you're doing quite well already.
If you're talking about the episode where they race to turn on the Blackpool lights, all three cars in that episode were Diesels.
Tune up would be the way to go IMHO. Might be worth having a look at ecomodders for some inspiration re the aero mods, but I'd try to get it running at its optimum before I thought about mods.
check out gassavers.org or ecomodders.com for more info than you can shake a stick at.
The recent mag with the aero article is a help too. There is a lot of tips there you can use (without the wings and down force)
Some narrow(er) tires helped my miata pick up a few mpg. Went from 14s to 13s and gained 3mpg, and yes they were the correct height.
Block off major air disturbances up front.
http://www.recumbents.com/car_aerodynamics/
clean up the aero- it's almost free and just takes a little time and creativity.
i don't have any hard numbers yet, but making a front airdam for my Camaro has allowed it to maintain highway speeds with noticably less effort than without. i just got the car, and have only ran 2 tankfuls thru it and keep forgetting to put my gas mileage notebook in the car..
on the 97 Cavalier i had, i blocked off the grille in the nose and used a piece of plastic to make a filler to take up the gap between the bottom of the bumper and the radiator support. i then cut out holes in the grill blockoff to allow just enough air in to keep the engine cool without the fan kicking on. that gained me almost 2mpg- from a steady and consistent 38mpg to just shy of my 40mpg target. i also took the passenger side mirror off at the same time, but i don't know how much of a difference that made. but i did notice less wind noise from the passenger side of the car without that big fugly mirror out there, so it did something.
somewhere along the line, i used a left over foam garage door seal to fill the gap between the hood and the nose and headlights. again, i don't know if that helped at all, but i don't think it hurt.
i also got rid of the stock air intake noise baffle inside the fender and made a really redneck looking ram air scoop out of a 3" home heating duct 90 degree elbow attached to the bottom of the driver's side fender. that was what got me up from a consistent 36.5mpg up to 38.
Nitroracer wrote:
Some narrow(er) tires helped my miata pick up a few mpg. Went from 14s to 13s and gained 3mpg, and yes they were the correct height.
Narrower tires help lower rolling resistance which is a MAJOR drag in stop and go driving.
I had a similar setup in my '92 Civic with the LS Integra drivetrain. In my experience, Honda engines (at least the twin cam ones) want to be at about 3000 rpms, so if you "keep it in 5th gear" there is a good possibility you aren't at that sweet spot.
Depending on whether you mean stop and start or engine on and off, you may find that letting it idle (if possible) makes more sense.
My newer Civic, with a stock drivetrain is rated at 32 city and 38 highway. I deliver pizzas and still manage 32 mpg, but just barely....sometimes dropping down to 30. Lately, I haven't managed better than 35/36 on the highway so I don't know what's up there.
I agree on the aero... lowering some can help too. Not only in making the car more slippery, but it can also make it so you have to slow less to turn.. thus you have to accelerate less
