When I first joined GS, I was gung-ho for testing and experimentation. It was during those first few months that I ended up testing Cylinder Deactivation, adding an EBH, and hotter T-stat (to name 3). Vehicle mods have increased the baseline from 26.x to ~30.x MPG. The rest can be attributed to technique.
With that said, I believe that a solid improvement in FE requires a foundation in vehicle modification.
To be honest, I haven't performed a good experiment in a long time. Between the ScanGauge and Davis CarChip E/X, data can be gathered for vehicle testing. It's been a while, and I miss it...
What I haven't decided is, what to test next? I really want to get back in the garage and under the hood, so to speak. Serious testing can sometimes take a hit in FE, which is OK.
Any ideas? Take a look at the garage under "Teggy" for current mods.
...and remember, good testing can be reproduced...
Mitsubishi Evo-style VGs on the top of the rear hatch to see if any Cd change is noted.
Sorry -- owned the 2003 Evo -- only aero add-on was the carbon-fibre spoiler, oh yeah...
Use the spring compressor things from JC Whitney and see if lower ride height give you lower Cd, as measured by coast-down tests or steady speed FE measurements.
Welp -- hasn't been changed in almost 130K miles, so may as well be synthetic, eh?
A/C vs windows down at 30 mph and 70 mph.
A/C feels cooler in both instances, especially at 99*F, with a dewpoint of 98. Oh -- FE...well, actually in this case windows at 2-3" down uses less fuel than the compressor, but is noticeably warmer. What about 80 mph coasting downhill?
Zoinks, that's going to take some work...
Have fun in Alaska.
U know it! Last State to check off in the collection. Full report to follow on the blog...
Regarding Houston -- I was there last week for a short work visit. Driving the highway means taking out extra life insurance! I admire your courage and FE...
Welp -- hasn't been changed in almost 130K miles, so may as well be synthetic, eh? Just because I haven't changed the lube in my MT in 120k miles doesn't mean a synthetic won't help, right? I mean, you don't use a toothbrush for 6 years just because it still has a couple of bristles on it. :-)
A/C feels cooler in both instances, Heh heh. My extensive testing indicates the same thing!
Zoinks, that's going to take some work... Ya, well... Think of it as making a plastic prototype for the metal pan you're going to put in when you rally the thing.
U know it! Last State to check off in the collection. Full report to follow on the blog... kewl
Regarding Houston -- I was there last week for a short work visit. Driving the highway means taking out extra life insurance! I admire your courage and FE... Ha, ya, it's sorta dog-eat-dog. I can usually find someone slow to hang out with.
I was just kidding around -- I'd really like to try the lowered springs, but the ride would be too rough. I saw "JC Whitney" and got concerned
Regarding the transmission: I have some concerns about changing the fluid. When the TL was having problems with its recalled transmission, I read in a few places that changing the fluid can be the "last nail in the coffin" before failure. If the synth will help, I'll definitely change it out...
A/C: Despite the large size of the windows, even full-down at highway speeds uses less fuel than the compressor -- that thing just completely zaps power. I used it a few times this tank, and already I can tell it's going pull down the FE.
Aero: I really need to get on an aero project of some sort -- I don't have a grille block or partial undertray yet. With the large amount of highway driving, it should only help. As far as Rallying, I think coroplast may fall off pretty quickly
Good ideas Bill -- another major project is getting cool IATs. The current plumbing isn't working so well...
I would like to see a good heated fuel test. Good data on fuel temperatures, intake air temps, fuel rail pressure, driveability and mileage data have been elusive so far. Gains in constant combustion (like boilers) is well documented, it just seems like gains are possible with compression/spark combustion as well.
So far it looks like heating fuel to about 200F is about the max at about 40psi before the fuel begins to flash off (boil). Juggling other variables like air temp, fuel rail pressure, ignition timing and a/f mixture to optimize the gain should give you the experimentors fix you are looking for - and prove or bust the theory!
Gains target, I think Mitsubisihi came up with an approximate 5% gain in using the head casting as a fuel rail, like an oil galley, in thier gasoline direct injection experimental engines. The gain was attributed solely to fuel heating, not the direct injection.
I would also like to see syn ATF tested. And actually, I'm trying to establish a baseline on this new (to me) vehicle I'm driving so I can begin syn ATF testing. I don't know how many logs would be sufficient to say "yep, thats baseline"
Anyhow, I'll definately participate on the ATF testing.
"You have to know the truth, and seek the truth, and the truth will set you free."
First, the current setup: stock intake box and tubing to the throttle body; K&N stock-replacement cone filter. I've experimented with hot air from the exhaust manifold in the Winter and currently, custom PVC piping to the outside air (which isn't working too well for some reason) -- probably not sealed and draws-in air from the engine bay. The inlet is near the wheel well.
I've conducted some tests with intake air temps over the last year or so. Original Thread. Here's what I've determined:
- Each vehicle model handles intake air temperatures differently
- The general exception to the rule: temperatures colder than ~40F require more fuel (multiplier in the ECU)
- There's an ideal range of temperatures for power, and an ideal range for FE (rarely overlap).
- Load vs. IAT can have an effect on FE
- You can fool the sensor (popular on Saturns) but monitoring knock on most models is a concern.
Right now "cooler IATs" mean less than 120F. Getting hotter than 110 starts to rob power and FE. The perfect range, based on daily observations, is humid air at 80-90F. The addition of a wet sponge in the airbox can draw air over it, cool the air, and add humidity. I planned to inject water to dampen the sponge, but it's close-quarters in the box, and the K&N filter tends to loose oil with the extra water.
I'm really leaning towards the Synthetic ATF. I need to dig into the shop manual for the process (haven't done this one yet).
Getting a decent baseline right now is tough. It's hot one day, cooler and rainy the next (and how much EOC-ing is available). I could always just use the 90-day average and go from there