Newb FAQ

[Red Tick]

First let me apoligize for improper placement of this thread, if infact it is in the wrong place. I saw only one other FAQ thread and was rather lengthy. So inorder to get maximium input I put it up front. Moderator plz move at your discresion.

Ok here is the skinny. These are basic things I have heard can effect MPG. I make no claim to any of these. I am asking if you guys could offer input and then maybe we can take agreed answers and rewrite them into a sticky FAQ thread for Newbs (like me).

Here we go, from the ground up.
(Of course each of these answers could very depending your application & setup.)

1. Fuel
a. Low grade fuel is cheap and moderatly efficiant
b. Mid grade fuel is a little more in price with best economy
c. high grade highest cost with best preformance with least efficiancy

2. Fuel Type (Gas vs Dessiel)
a. Gas delivers ok to good economy
b. Dessiel good to great

3. Winter Fuel vs Summer Fuel
Does the fact that companies in the U.S. oxyaginate fuel durring the
winter hurt your MPG

4. Wheels
a. Slightly taller tires improve MPG
b. Wider tires hurt MPG do to a larger footprint (Surface area contact)
c. Lighter rims Better MPG vs Heavyer rims Poor MPG
d. Proper air presure in all tires will improve MPG

5. Suspension
Does suspension effect MPG in any form. i.e. lower ride hight less drag
better MPG

6. Engine Componets
a. Engine cooling i.e newer more efficiant radiator and fan will improve
overall preformance resulting in slightly lower MPG
b. Improving air intake and exhuast will improve preformance and depending
on how that application is tunned might result in slightly improved MPG.
(Basicaly more air in higher oxygen fuel ratio requiring less fuel, more air
out les resistance. Better preformance.)
c. Speed effects total MPG. Best average of speeds 50-60mph depending
on car type yields better MPG
d. RPM shifting at slightly lower RPM's can save gas, i.e. not hotdoging it!
e. Manual is better than automatic for MPG (on average remember newbs
here)
f. Those tornado things you jam in your air intake hoses? (as seen on tv)
g. Keeping your Carb or injectors clean.

7. Car body
a. body kits and or wings improving airflow resulting in minnor MPG
improvements.
b. overall wieght lighter means more MPG

8. Flux Capasitor
a. Just kidding...

Ok just some basic things I have heard before. Are they ture or false and what is better? Remember these are basic concepts for the average newb and their average car. I understand some cars will yield better results with diffrant aproaches than others. Just some things the average guys or galls can do to get better MPG. So if we can get some agreed apon answers we can get a basic newb FAQ

[GasSavers_Jack]

WOW! What a mouthfull that is. Ok here is my take on what I can give a take on (if I am wrong someone yell please)

3. Summer fuel better for MPG

4a taller tires are like longer gearing in tranny so yes
4b yes
4c yes
4d Lower air pressure then normall (bad MPG) Proper air pressure better MPG Higher Air pressure better MPG but that most likely works out Hyperbolicly so the hirer the air pressure the less improvement you get per pound of increase

5 debatable

6c lower MPH = Higher MPG
6f Tornado = waste of $60
6g yes

7 Better aerodynamics = less resistance = better mpg
7b less wieght = less to move around so less energy needed to move it

8 unprooven (Untested too I would guess)

[95metro]

Well, somebody is bound to beat me to a lot of these, but here goes:

1. Fuel

Octane-level is ONLY to keep gasoline from pre-igniting. If your ignition is too far advanced it will probably cause your fuel to pre-ignite and cause knocking. Octane (MTBE, Ethanol, etc.) simply raises the pre-ignition temperature of the fuel and doesn't change it's energy output.

2. Fuel Type (Gas vs Dessiel)

Gas and diesel engines are completely different animals. Gasoline is formulated to not pre-ignite (see above). Diesel is designed to pre-ignite. Diesel has very high-torque at low rpm, but a very limited rpm range due to high compression ratios. More low-band torque will generally mean better fuel economy.

3. Winter Fuel vs Summer Fuel

Debateable as to the % this affects FE. Cold weather is the primary FE killer, but there are more reasons as well.
http://www.metrompg.com/posts/winter-mpg.htm

4. Wheels

This needs to be quantified on the site. Yes, taller tires/wheels will probably have the same effect as swapping transmissions, but may decrease performance or have other adverse affects (speedo adjustments, etc.).

5. Suspension

Yes, lowering the car reduces the overall frontal area, but actual FE gains haven't been confirmed yet.

6. Engine Componets

For starters, see this site: http://www.fuelsaving.info/index.htm

Engine cooling: warm air is better for FE
Intake/Exhaust: this needs to be tested for confirmation
Speed: Absolutely. Slower is definitely better, but most vehicles seem to have a "sweet spot".
Shifting: Highest gear = best FE (I believe krousdb confirmed this)
Trans Type: Manual is better (perhaps the odd case where it is not) - especially for hypermiling techniques.
Additives/"FE" devices: Most of these can be debunked. See above link.
Clean carb/injectors: needs to be quantified, debateable how "dirty" they actually get

7. Car body

Body kits: I have heard of some that actually increase frontal area of the vehicle, thus, worse FE. Aero mods may not look as pretty, but they certainly seem to be working.
Weight: Yes, less weight, better FE.

8. Flux Capasitor

Oh, Mr. Fusion? Yeah, I've got one in my basement in a glass of water.

[Red Tick]

Great info guys!! lets keep it going..

[SVOboy]

Ah, I dunno what exactly is left, but let's see...

As for bodykits/lips: if your underbody sucks these are good because they move air out of the bottom which sucks, but when you make a full tray and your body becomes good it is better to have the air under there than the additional area of the lip and the disturbance it causes sitting in the way of the smooth surface.