The Hypermiling/mpg Thread

[Tygen1]

He's just bragging cause he's got four extra cylinders

[AZN_ZX2]

He's just bragging cause he's got four extra cylinders

Guilty as charged. I do get 25 highway though somehow.

[Tygen1]

Let me add something usefull.

Getting better mileage is a pretty simple idea. You need to make your car or your driving techinique more effcient.

For the car you need to address three areas. Aerodynamic Load, Road Load, and Parasitic Load.
Aero Load is one of my favorites. It's pretty straight forward and already well developed. Everything you need to know is on the net and has was all figured out by the 1930's. They have not learned anything new about automotive aero since then. Teardrop shape is what your after. Aero Load can be calculated as CD (Coeffcient of Drag) or CDa (Coeffcient of Drag Area)
Road Load refers to your cars interaction with the road via. the tires or gravity. Low Rolling Resistance tires work, but you gotta get pretty radical to see a significant and money saving difference. Low friction bearings, light wieght wheels, and the total wieght of the car effect road load. Road Load can be calculated as Crr (Coeffcient of Rolling Resistance)
Parasitic Load refers to all the loads that are not required to propel your car down the road that are taking HP away from your motor. A/C, P/S, Water Pump, Alternator, etc... You could also expand this thinking into the motor, low friction coatings, light wieght parts, oil pump, etc... This can be calculated as HP (Horse Power) This load is more difficult to figure out, but can be done.
Look here to learn more about these: http://ecomodder.com/forum/showthrea...ower-6341.html
There is more out there, but this is a good start.

Changing your driving habbits can be a bit controversial. I'll list a few concepts:
Drive as slow as possible in the highest gear possible.
Keep your motor on as little as possible.
Don't touch the breaks.
If MTX, accelerate at 75-80% throttle opening and shift at 2250 rpm.
If ATX, accelerate at a rate which allows the transmission to shift around 2250 rpm.
Don't use cruise control on the highway, keep a steady throttle position and let the car slow down going up the hill.
Drafting can help, but no one will be driving as slow as you It's more effcient to drive 50mph solo than 60mph drafting.

Look here: http://ecomodder.com/forum/EM-hyperm...ecodriving.php
and here: http://ecomodder.com/forum/fuel-econ...ifications.php
for more details.

There's a lot more to it, but I figured I'd throw out some things that are at the top of my head. It would be nice to develop a list specific to the ZX2, however the tip's listed in the links apply to all cars.

I'd say the ZX2 is a good car to get great mpg with. However, just like with performance, the Honda guys got the best options out there. We can only mimic many of the performance or effciency mods that work great with them. Were locked into this one motor design and car shape, so we gotta do with it what we can. Aside from really radical motor or car shape changes, we will probably max out in the 70mpg range...if you go all out. Yah, I know you guys are laughing at me cause that number is insane high, but in the Ecomodding world, it's only the begining. I'm hoping, that when I am done, I will be able to get high 70's on the highway and nearly equal that around town

[mechtech]

Aerodynamics have a big part in MPG.
But in real life only after 45 mph or so.
Around town just won't benefit much .

The hot air intake is full of danger. You will lose power for sure when you need it.
And good luck with engine knock/pinging!

Some basic stuff for our cars is:
5-20 oil [anybody's brand]
Put the tire air up 3-4 lbs over the factory recommendation. This low increase is very safe and will help.
Brake drag. Make sure your brakes are releasing!
This is huge-- Tire alignment! This can really kick up your gas mileage. This is a hidden cause of why one car is so much better than another. A little toe in the back, and zero or a little toe out on the front.
I use MMO or 2 stroke oil in the gasoline. What?? Sure. Lubes the pump with alcohol gas and helps seal rings and valves. Just 2-4 ounces /10 gallons fuel, though.
YOUR RIGHT FOOT! #1 for sure. Thinking like there is an egg between your foot and the gas pedal that you never want to break is a very good approach. You will step on the gas as little and as slowly as possible, for your needs.

And finally, mechtech's IAT mod can certainly help .

[Tygen1]

Good point Mech and good to see you back!

Aero benefits start in the 35-40mph range. Don't be shy, put on some skirts and find out
Everyone should do aeromods because they help in many more ways than just Aero: Faster Warm Up, more stable opperating temps, more downforce and stability, quieter ride, etc...

I'd agree on the warm air intake, it's not worth trying unless you have some real data gathering equipment. Maybe someday I will be able to do this on my WAI.

The egg under the pedal thing doesn't apply to acceleration. Accelerating is most effcient as I stated above. Then after that, you want to just hold the "Load", which could be described as an egg under the pedal. I just hold the pedal steady on flat ground and uphill, down hill I coast or taper off the throttle to keep from going too fast. I use a ScanGauge II and monitor LOD (Load). The ScanGauge or equivalent instant MPG display device is a great tool, I'd say invaluable if you are serious about saving gas and money.

[AZN_ZX2]

mechtech and tygen you two are too smart. Go invent a time machine or something.

[LmidgitD]

Haha, that's why I wanted them in this thread. These guys have made the mistakes that the rest of us don't want to make, and so they know the right way to do things. As a side note, if anybody has a scangauge II and wants extra codes, like a handy average mpg per tank?

http://www.scangauge.com/support/pdfs/XGAUGE.pdf

I have unplugged the vacuum line coming from the air intake tubing and leads to the brake booster. Since that mod I have noticed that my mileage has gone up a bit. Please keep in mind though that this is my second fillup since getting the SGII so my improved driving habit prolly has helped some as well. I'm still basing mpg numbers off the trip odometer, not the SGII yet because I don't know if it's spot on yet.

[only S/R]

I have to say, driving slow seems to hurt my milage. im not varying the throttle either, im holding steady and accelerating litely just to hold a speed, and anything below ~60 seems to murder my milage

also, ive noticed just getting to speed briskly helps most, not fidling around worried about hitting the right gear and the right speed, hell some of my best city milage i dont use 2 3 or 4. this is on the basis of if you accelerate at 4mpg for 5 seconds, or 7 mpg for 15 seconds, both stopping at 40mpg cruising, then ill take 4mpg for 5 seconds.

only have to agree that the aero makes the biggest difference, no one has added the the air vortex behind the car is the main issue. when a car is going down the road there is turbulance behind it that actually pulls it backwards,just like brake drag, destroying this turbulance/vortex is why the prius and alot of new mpg cars have the high assend. this is also why a pick up with no topper and the tail gate up is the best way to go. mythbusters proved it... look it up. the air rotates in the bed and allows oncoming air to move easier over the truck.

i plan on a front grill block, wai(not hai) im going to pull air right beside the coil pack, which in most any car over 35mph will be outside air temp neway. i have a small vac leak on the brake booster valve, a vac guage, and im running 35psi in my snow tires. i have a feeling the snow tires are keeping me from 40+ mpg

im going to try this "75-80%" pedal while shifting at 2500.. seems pointless, floor, shift, floor, shift, floor, shift its like driving semi

[iceracer]

In one ecco run with my SR I got 59+ mpg.
Blocked off the grill to maintan app.200 degrees coolant tempearture which also raised the intake air temoerature.
Raised the tire pressures to 40 psi.
Drove in 5th gear at 45 mph. Coasted on hills as much as possible in neutral, let the engine idle. The handling of the SR helped on some of the curvy down hills.
Every thing else is pretty much what tygen and mech said.
One thing to remember also. Idling gets 0 mpg.
I'm not in full agreement with not using the cruise control. There are pro's and cons. My SR didn't have it so it was not an issue but I have had others that did.

[Tygen1]

Only S/R, get a Scangauge or UltraGauge and you will see how speed effects your mpg. I've found that my car get's the best mpg in the 50-55mph range. I can get better instant numbers in the 35-40mph range, but can not pull hills at that low of rpm so I need to down shift or lug it soo hard that the mpg's drop way down. 50-55mph and I can climb most any hill at greater than 50mpg and can carry 65-70mpg on the flats. However, it has finally warmed up and this morning I was seeing low 70's on the flat and my LOD was way down. In the 35-40mph range I will see 80-90mpg instant readings

For low rpm/high throttle accelerating, you probably won't see any large benefits, it's just optimized and you are using the fuel more effciently. It's not conjecture, it's a well understood fact. But it will come down to your skill applying it to see a real benefit. In city driving, you gotta coast as much as possible, and this type of accelerating will work well with that. If accelerate that way out to the highway, then spend 70% of your trip at a constant speed, you probably won't see any benefit.

It is well understood that the turbulant wake behind the car is the largest source of drag. There is not a whole lot we can do about that with our car, unless you want to reshape the back end. The Prius is far from optimal, the Orginal Insight is a bit closer. Go here: http://ecomodder.com/forum/showthrea...rt-c-9287.html to see an ideal form and here: http://ecomodder.com/forum/showthrea...ists-7118.html to read for a couple hours I have messed around with trying to fix the rear wake issue, but have not yet been successful. Cleaning up the front and sides has been very successfull. We have four big areas to address: The Front, the Turbulant Wake at the rear of the car, the swirling vortex after the "C" pillars and the turbulance at the side of the car. The front is simple, just block the grill, but you could do a bit more to relieve the large stagnation area you just made by extening the nose down a bit to force that air over the car. Our rear window is much too steep, so you would have to reshape it or add a long visor The "C" pillars wrap around so gently that it causes a strong vortex (you can see it in the rain), you would have to make this visor wrap down the sides and have a clean cut off point vs. gently wraping curve. The turbulance at the side of the car can be cured with air dams in front of the wheels and covering the wheel wells with skirts...this is where I have been successfull. There are other factors, but these three are the big ones.

Higher tire psi is also a noticable improvement. I run 50psi, but I'm a little off the deep end I also have tires that work well at the psi. Years ago I ran my stock tires over 40psi and found that brakeing and handling both improved, I could have cared less about mpg's at that point. 32psi is just for comfort.

[mechtech]

Yes, accelerating a bit briskly can be better.
You are not in the lower gears for as long!

[only S/R]

hmm, link to scanguage you are all using?

[LmidgitD]

http://www.scangauge.com/products/

There are cheaper ways to do it also, but you'll have to put a little work into making them work. I just figure that if I ever see the need to sell the SG, it resells for around $130. Not too bad.

[Tygen1]

I'm pretty excited because my last tank of commuting was my best ever! 55.4mpg over 464.5miles
The mods done last winter are really paying off

[iceracer]

You can buy low rolling resistance tires almost any where today. Car makers are getting into the Eco stuff also. A lot of it is aero. Grille blocks etc. Interesting times.

I just filled up my Fiesta yesterday. 407.8 miles and 10.75 gallons. 37.935 mpg. This was just everyday driving.