whats the easiest and fastest way to get more than 33 mpg?

[Vanilla Sky]

I know, but that's the only way you can really see what they're thinking. IF there is evaporation occurring, it's going to be so small that it doesn't matter.

However, I have to say that in our new car, which has an onboard computer that calculates fuel used, the longer we go between fills, the bigger disparity between the measured fuel economy and what the computer says. I don't put a lot of faith in the onboard computer, but that's another example cited in hypermiling circles regarding evaporation.

[lostforawhile]

Well, I dunno where you live, but my gas mileage is pretty consistent year round. As it is for everybody I know in my area... I dunno what kind of additives they use where you live, but a 35% decrease in mileage is hugely drastic. I've heard of an extra 5-10% ethanol in extreme cases, but even that shouldn't cause that drastic of a fuel mileage decrease.

Also, I doubt that the pump speed will produce any measurable difference in fuel output. The pumps are checked and verified for accuracy regularly by a regulatory body. Notice the inspection stickers on the pumps. And how do you know that running the pump slower doesn't introduce more air? What if it's a submersible pump in the tanks? Then I don't see how any air could get pumped in at all...

If were going to get into hypermiling, I'm out of this conversation. It's not practical, and unrealistic to do on a daily basis.

EDIT: Sorry Vanilla, didn't see your post until I posted. I don't know if your Nissan was fuel injected or not, but definitely am just speaking in terms of EFI cars. Carb'd cars run better with the air at a certain "warm" temperature because the fuel passing through the barrels and manifold will atomize and stay atomized better. Whereas an EFI car doesn't have this problem since the the fuel injectors atomize the fuel fairly well, and inject the atomized fuel directly into the ports in the head. Meaning less time for it to cool and puddle and stick to the passages in the intake manifold. Hence the reason the Carb'd 3geez and 2geez have that hot air tube coming up off the exhaust manifold with the temp regulator valve keeping the intake temps around 100 degrees.

correct, fuel injected cars measure the outside air and adjust the fuel accordingly, the computerized carbs on the three g do this to an extent, but not as well, they control the air injected into the manifold to adjust mixture, and one of the parameters is the thermoswitch in the air cleaner,as well as a couple of vaccume thermo switches on the engine.

[kentwat]

I drive the sh1t out of my 86 lxi and i average 30mpg. Granted this is mostly city miles usually max rpm 3500 sometimes i buzz it up around 4000 but usually its the 3-3500 range. 5 speed no mods and pgm-fi light on with a quality code 12 stored. Im very happy with that since it comes with no car payment. I've tried the 2k shifting theory and I didn't see any improvement in mileage. It was just a long 300 miles.

[Tomisimo]

I live in mountains and we have curve roads here and I still manage to do 34-35mpg.. if you ask me thats pretty good for a car with moonroof, all electric and 4 wheel disc brakes.

[Vanilla Sky]

EDIT: Sorry Vanilla, didn't see your post until I posted. I don't know if your Nissan was fuel injected or not, but definitely am just speaking in terms of EFI cars. Carb'd cars run better with the air at a certain "warm" temperature because the fuel passing through the barrels and manifold will atomize and stay atomized better. Whereas an EFI car doesn't have this problem since the the fuel injectors atomize the fuel fairly well, and inject the atomized fuel directly into the ports in the head. Meaning less time for it to cool and puddle and stick to the passages in the intake manifold. Hence the reason the Carb'd 3geez and 2geez have that hot air tube coming up off the exhaust manifold with the temp regulator valve keeping the intake temps around 100 degrees.

Nope, Nissan was EFI. The difference between warm air and cold, damp air was almost 2 MPG. In the Summer, the difference wasn't there at all, just in the coldest parts of the Florida Winter.

[2ndGenGuy]

Was it direct port or TBI?

[Vanilla Sky]

Multiport, very similar to the setup the 3gee has, but with a horrible intake manifold design

[ecogabriel]

I live in mountains and we have curve roads here and I still manage to do 34-35mpg.. if you ask me thats pretty good for a car with moonroof, all electric and 4 wheel disc brakes.

I only checked highway fuel consumption on my LXi auto once. In a short drive (40 miles) I estimated about 30 mpg. I am OK with it; EPA estimates for the time the car was new were 27mpg highway. A loosened engine may have less friction and thus run a little more efficiently,
The numbers you suggest sound reasonable for a couple of reasons: one, if yours is a 5-speed you may easily gain another 10% in gas mileage out of using a stick instead of an auto -marginally lower car weight, lower transmission losses (no torque converter that would sap power). Two, different regulatory requirements may make your car lighter in weight than the american counterpart.

But I consider really improbable going beyond 40 miles per gallon.

[-DWM-]

I regularly get 32-35 mpg in my 89 LX-i. That's with a short ram intake, bad motor mounts, and small oil leaks, using premium (93 octane) fuel.

[lostforawhile]

I only checked highway fuel consumption on my LXi auto once. In a short drive (40 miles) I estimated about 30 mpg. I am OK with it; EPA estimates for the time the car was new were 27mpg highway. A loosened engine may have less friction and thus run a little more efficiently,
The numbers you suggest sound reasonable for a couple of reasons: one, if yours is a 5-speed you may easily gain another 10% in gas mileage out of using a stick instead of an auto -marginally lower car weight, lower transmission losses (no torque converter that would sap power). Two, different regulatory requirements may make your car lighter in weight than the american counterpart.

But I consider really improbable going beyond 40 miles per gallon.

the dx is a lot lighter factory too, if you aren't going to use the ac,ditch it, it's very heavy!! and switch to one of the lightweight batteries like the odyssey. well worth the money, and much better reliability. by eliminating 20 pounds at the battery, and ditching the ac, my car still weighs less then factory, even after adding everything i did. of course I got rid of 50 pounds of vacuum nightmare and all my parts are lightweight aircraft alloy. When I get this thing running it'll be interesting to see my mileage, SU carbs are very efficient,since the piston adjusts to driving conditions. They act like you are using a smaller carb for cruise and a larger carb for acceleration

[ShyBoyCA6]

damn dwm isnt that a lil high for a 21 year car???

[lostforawhile]

I call bs as well , most prius owners claim about 45mpg and Fit owners claim 35-40mpg, Its highly illogical that your 20 year old car gets better gas mileage than almost every new car (including hybrids: see government website about prius mileage ---> http://www.fueleconomy.gov/feg/calcu...ta&model=Prius)

In order for the a20a3 to get around 45 mpg, you would average about 540-720 miles per gas tank (12 gallons to 16 gallons i don't remember exactly how big the tanks are). Thats hard to believe performance coming from a motor that makes ~110-120 hp @ they flywheel (and power loss is about 10-15% in FWD vehicles which would make 93.5-108 hp to the wheels) now you taking out the cat and adding an intake would only add a little bit of power (and could potentially lose some) but for the BOTD ill give you ~120 at the wheels. Now add that together with a car thats curb weight is ~2500-2750lbs and you have a car with a power to weight ratio of 20.83-22.91lbs/HP and a motor whose efficiency is in the ballpark of 60HP/L.

To put it into perspective Im going to compare your car to a Fit since they are both NA (and not hybrids) a 2010 Honda Fit has a curb weight of about 2500 pounds and an estimated mileage of 35mpg highway (09' fit owners claim 39 so we will meet in between and say 37mpg highway as an average.) Its powered by a 1.5 liter that makes ~ 105 to the wheels. It's power to weight ratio is 23.8lbs/HP and the motor efficiency is 70HP/L.
To recap:
Fit: 23.8lbs/HP 70HP/L (17.9sec @ 75.7mph 1/4mile) mpg: 39
Accord: 22.9lbs/HP 60HP/L (17.3 unknown trap speed) mpg: 45?

How is it that a car with a more efficient motor, that is more aerodynamic and has more economically friendly gearing than the accord gets less mpg than yours? (not to mention that no one else on this forum gets anywhere near what you claim) granted the fit doesn't make quite as much power to weight but thats not enough to bump it that high. *my calculations do not include drag coefficients, trans gearing, tires used, or climate.

so anyways ba109296, show me your simple math of how you get gas mileage because frankly i'm confused. So unless you are getting 700 miles to the tank (i only get about half) and can prove it. you might as well just quit trying and stop trying to be macho with the mods

ford is bragging about their new cars getting 25 mpg, don't complain. the early civics got amazing fuel mileage, many people reported the 1200 models could get close to 50 mpg, and this was in the seventies. of course they didn't have heavy navigation systems, climate control systems, video screens, dvd players etc. etc, whats happening is the engines get more efficient and more powerful,but they keep adding more and more crap. so the fuel mileage stays the same, and the performance stays the same. if they would make a basic stripped down fun to drive car, they would probably have killer fuel mileage. but everyone wants 20 cup holders and a video screen for the kids.

[-DWM-]

damn dwm isnt that a lil high for a 21 year car???

I thought so too, but I do the math at the pump every time. Maybe I'm a really efficient driver. I also fill my tires to 32 psi, and I still have fresh plugs/wires/cap/rotor.

[ShyBoyCA6]

I thought so too, but I do the math at the pump every time. Maybe I'm a really efficient driver. I also fill my tires to 32 psi, and I still have fresh plugs/wires/cap/rotor.

same here but i pump 89 octane fuel from chevron i got new plugs new cap and new rotor but same cables (looked new when i bought it) and i fill it all da way and it last me for 2 weeks and a half and mods are a custom short ram intake with a air duct hose connected to air filter and ngk iridium but if i get my exhuash pipe fixed i know that my girl will hual more ass and be a better gas saver i probably get like 28 mpg on the street it hardly goes down highway like 34 mpg