40.3mpg in a 2001 Cavalier
 

I broke 40 mpg today. I don't know how much better I can do in this car but I am happy so far. I have a ScanGuage on its way so I hope I can squeeze a few more MPGs out of it. This car is quite the little mpg sleeper.

you got me beat. probably because of the stick shift.

if you want to go above and beyond, check out my garage and see what I have done. most of it is easy to do and yields pretty good numbers. the scangauge is a good place to start

*edit* you can also completely block off the front of your car. 90+% of your cooling comes from under the car. I blocked off the bottom of the car and instantly started to overheat. I ripped that part off. also I left a place between the hood and the bumper so that I could still open the hood. these cars also react well to the WAI. (in this, I am assuming that the 1997 and the 2001 are the same or at least similar enough)

Congratulations on the 40 mpg. Based upon my experience you definitely can squeeze more out of you car. I have a 2003 Cavalier and have been pulling off some amazing numbers this summer--check my fuel log.

Key to success has been picking routes that let me EOC as much as possible (I have a switch that kills power to the injectors). I have found a route that except for one 7 mile stretch in 45 miles, I can EOC like crazy. I've calculated that I'm coasting about 70% of the time. I'm not sure what the impact will be on my clutch/drive train, but EOC has boosted my economy tremendously. I can pull off 50 MPG on short errands around town. I can pull off 70 MPG on longer trips.

BEEF is correct on grill blocking, but only do it after you have a Scangauge. You don't want to cook your motor. I have rigged up a switch that lets me activate the cooling fan at will. I turn it on whenever the coolant temp is 200+F. I turn it off when it drops down to 195F or less.

A front belly pan has worked well for me (look at last summers vs this summer's MPGs). I've made mine out of fiberglass shower wall ($30 at Lowes). It's durable and easy to work with. Just make sure you don't fully close off the underpan, but leave a slot in it for the radiator air to escape. My opening is adjustable, so in cooler months, I can close it off some.

I believe that I have not yet tapped out everything in my car. I think it is a possibility with my route, driving style, and upcoming, to average 75 MPG during the summer months. In winter, I hope to average around 60 MPG. We will see.

Gotta love that pushrod 4.

The only real difference between the 1997 and the 2001 is the transition from batch fire to SFI in (I think) 2000.

I've been wondering if you'll ever post! :)

phleas,

I'd like to know how you did some of the stuff to your car. did you ever disable the daytime runners? how about the vertical windshield wipers.

I have an auto so I am sure that I won't ever see the numbers you are seeing but I would love to get closer.

thanks

BEEF-

The DRL fuse has been pulled. This leaves the daytime lights off, but illuminates a service warning light on dash. I can live with this.

The one vertical wiper...doesn't bring much if anything in terms of FE. I did this by removing the wiper fuse. I cut an old wiper fuse in half and saved the prongs. With these prongs, I soldered onto the ends of two pieces of wire and made it possible to plug back into the fuse box. In one of the pieces of wire, I installed an inline fuse, same amps as removed for the wiper. From this fuse and the other piece of wire, I installed a toggle switch. This setup enables me to start the wiper motor and leave the wipers in any position.

My wife has a 1999 Cav, Auto. The best I can get out of her stock, non-hypermiled modified car is about 37 MPG. The automatic really hampers potential.

Google for the DRL module (I think it's a sub-module of the BCM). You may be able to disable the DRLs without getting the dash light; GM's design for that stuff is usually pretty malleable.

On the Cavalier it's actually stupid easy to disable the DRL. If you disconnect one of the high beam lamps you disable DRL because all it does is run the high beam lamps in series.

....so then what do you do for high beams?

I'd rather not go around with just one headlight. I think i will try pulling that fuse.

the wiper thing was more of a curiosity. it also makes me feel pretty good that the best you can do on your wife's is 37. that means I am doing alright.

any other advice would be greatly appreciated. I am running about 45psi in my tires and I have a complete grill block for the bottom and weather stripping at the top along with a WAI and an airdam. I did put smoother hub caps on but I don't think that did much (if anything).

when I first saw your car in the top 10, I didn't really believe it until I saw all the mods. that gave me hope of getting a lot better on my car. I started with 30mpg and am now at a running average around 36.5mpg.

didn't mean to highjack the thread but we are still talking about cavaliers.

Interesting way of doing the wiper mod. I like that its easily reversed.

-Jay

You don't go around with one headlight. The low beam and high beam bulbs are separate in that vehicle.

The high beams would be cockeyed but that's all. The high beam switch turns off the DRL system and they run like normal lights.

i am fairly sure that there is a combo bulb... but did some google action and came up with this:

All you have to do is locate the Body control module located on the drivers side kick panel ( in front of the door, by your feet) once you are there, there are three connectors that plug into it. the middle plug has two rows of pins. The plastic keepers are lettered "A" and "B" unplug the center plug (the dome light will go off when you do this) locate the "A" & "B" markings on the darker blue portion of the connector. On the "B" side row of pins, there is a dark blue wire six spaces over from the one side, seven over from the other. Cut this wire and simply add on a piece to the side that goes to the module connector, long enough to reach any good ground lug, like a screw in the metal part of the dash. Connect the wire to ground, and inside the body control module, it see this to mean that the regular headlights are on, and so it energizes the relay that turns off the DRL's. That's it, try it, it works perfect, NO side Affects. I tried the relay trick before this, and was not happy with all the added stuff I would have to do to get around the side affects. besides, I can put this back as easy as splicing a wire back in place. So PLEASE try this, and save Fuel, and my eyes, because you might be driving on the same road as me some day, and I won't blind you.
Note: one reader reports that if you want to add a new remote for keyless entry you'll need to revert your DRLs to normal to add the remote.


this is for the 2000 and it might be different on other years.

I'd say to investigate the high beam switch, which (at least in my GMC) is a huge tangle of tiny wires that do a million things in ways that don't make sense (ground something when you expect +12v, give +12v when you expect it to be dead, etc), but someone did the googling I suggested...

See? Toldja so! :p

not bad. don't forget to put it in your garage so we(and you) can follow your progress.

otherwise this skeptic group may call it a fluke or not a complete fill. ;) seriously tho, well done.

being a cavalier owner myself, I can totally believe those numbers. I have the 4-speed auto which kills my potentian. as phleas said, the ceiling seems to be just under the 40 mark.

the 5-speed gives so much more potential. with EOCing and coasting like crazy, I can see those numbers going through the roof. I guess I am a little biased because I own a cavalier. I'd love to hit 40 legitimately myself. I have it 40 but it was a short fill (and I know it). I have hit 38, that made me smile.

I would still start a gas log just to keep up with it if I were you. that way, you can share the love. I hope to help out other cavalier owners (and sunfire I think) and hope to steal some ideas from others.

Another Cavy owner here. I have the base three speed variety, and have pretty much maxed out the car as far as I want to take it for now. If I had the know how I would throw a five speed in it, and to really make it go the extra mile, swap in a 1.8 liter. :D At that point though I'd be better off just finding another car for cheap with that combo already.

phleas, you are an inspiration. Hopefully someday I can pick up a cheap five speed Cavy and give you a run for Cavy MPG champ!

Edit: Here is a thread on J-body.org about disabling daytime running lights. Not sure if you have to be a member to view it or not.

https://www.j-body.org/forums/read.ph...0&t=326113&p=1

I think every cavalier owner here has been watching phleas and stealing his tricks if we can.

mine is the 4-spd auto trans

just out of curiosity, what motor and tranny combo does everyone with a cavalier have?

i have the 2.2 OHV 5 speed.

2.2 OHV 3-speed here. :(

same setup only with the 4-speed.

I don't consider myself as an inspirationalist. I'm just a very frugal engineer who is trying to take his Cavalier as far as possible on a drop of gas!

The folks who have inspired me the most to try this hypermiling stuff have been Basjoos and CO ZX2. CO ZX2 used to post much, but I haven't seen anything from him in eons. I would read his posts and then steal some the the ideas shamelessly, while remaining a silent lurker.

I can say that pulling off fantastic mileage is a combination of car, driver, and route. I have a pretty good makeup. My car as stock can deliver decent MPGs. With some minor tinkering (e.g., tire pressure to 55 PSIG, EOC injector switch, grill block, scangauge, WAI, underpan, wheel skirts) the car is even better. As a driver, the key is anticipation and moderate acceleration to get into high gear as soon as possible. I "Fred Flintstone" and coast out of my driveway in the morning. Taking a route that is free of traffic is very, very important. The lack of other drivers lets you hypermile more easily. I have a fairly "clean" route to get back and forth to work.

Couple all 3 of my factors and the result is great, unfathomable MPGs.

great, unfathomable MPGs.....no doubt.

my commute is not so friendly to those conditions. I live outside of the city but work near the airport so traffic can get pretty ugly at times.

you said you were an engineer, what field? I am in electrical engineering (I am a tech not an engineer) I work with the engineers here and help design PAs for cell phones and other wireless devices. right now we are designing a wimax PA for a laptop internet card.

chemical engineer

2.2 ohv 5 speed

Great job phleas, keep up that eoc. Usually on the road i have to cut short my eoc because of lights, traffic or pedestrians. With a route with no other traffic would allow one to fully coast to get that extra distance. I believe that the Priius that got 102 mpg on a closed course actually used fuel at 56 mpg and coasted the rest of the way. They found that it worked best at 40 mph down to 33 mph. Thats why i search for the least traveled route.