Modifications for increasing mileage

[Moondawgy]

I've seen a lot of threads on modifications for increasing power, etc., what about modifications for the specific purpose of increasing mileage?

Please share your thoughts and experiences regarding the things we can do to increase mileage by modification:

• Air filters (I have read the ad infinitum thread on this) My understanding is that this helps with mileage but may increase engine wear and decrease engine life (the question remains whether the purported damage is significant over the long haul/anticipated life of the vehicle?)
• Silicon Air Intake Hose- seems easy enough?
• Cold Air intake - seems costly?
• Exhaust mod?
• Tire pressure - I know its not a mod, but what is the best pressure for mileage, my guess would be max?
• Anything else?

Thanks for sharing your expertise,

Moondawgy

[gabe1475]

I seem to recall others having written about this, you should be able to reprogram the ECU for a lean fuel mix, although not sure how effective it would be as I have not tried it. Vendors claim 5-10% increase.

Not sure if the products that add more power would actually add more mileage (cold air). Others can chime in on that.

I go to 44 psi. Also for those that are going to say this is not safe I have attached a link showing the benefits of higher PSI. The only loss is in comfort. I think max psi is ok as long as you do not have an issue with a slightly harsher ride. If the roads in AZ were not excellent, not sure I would want the psi as high as you would putting more wear on the shocks.

Driving Under Pressure (full article) - CleanMPG Forums

[mvaldes]

K&N of BPP air filter, air scoop, and forge air intake pipe will probably get you a couple extra mpg. (It did for me.) I like my DTH exhaust, but don't think it changed anything in the mpg department.
You can also go the scangauge route, and use it to teach you more efficient driving habits for you particular smart.

[jefferios]

I usually put in an extra 2-3 psi in my tires, anything more is too harsh. Also I believe my traction in the snow is decreased if I go that high.

[rfernatt]

I'll add a few more possibilities, but I only have the cruise and avoid ethanol when possible:

- Low roll-resistance tires as used on hybrids
- Different engine oil that improves mileage (I don't recall the special fuel efficiency rating), but you have to go to 5W-30 I think as it's not available in 0W-40
- Cruise control
- Avoid or minimize ethanol in gasoline use

The best change you can make is your driving habits (coasting to or avoiding stops if possible, looking ahead, planning your route, steady speed around 55 mph, etc.), and that's free! Also, using a MPG tracking/logging mechanism can help identify trends with certain fuel brands, bad driving routes, etc. I keep a paper log and one on Fuelly.com:

[jwight]

smart USA has this info: http://owners.smartusa.com/userfiles...%20Economy.pdf

[Old smart]

Originally Posted by rfernatt

... - Different engine oil that improves mileage (I don't recall the special fuel efficiency rating), but you have to go to 5W-30 I think as it's not available in 0W-40 ...

Doesn't specifically have to be 5W-30, but the thing to look for is the "Fuel Conserving" starburst or that it is ILSAC GF-4 compliant. Saves about 2% fuel consumption. No 40-weight is GF-4, nor is any oil with a winter viscosity above 10W. Mobil 1 5W-30 is GF-4; Mobil 1 0W-40 is not.

[headless]

1 Strip out the carpet
2 change the seats for lightweight carbon seats
3 don't give anybody a ride, saves weight
4 buy lighter wheels
5 loose weight, (you know you've been piling on the pounds lately anyway)
6 tape up all the seams and joints on the car to make the car more aerodynamic
7 drive really slowly everywhere you go, no sports starts and coast as much as you can
8 drive in auto as it is set up more for economy



BUT WHY WOULD YOU WANT TO ANYWAY, JUST HAVE FUN

[chumly]

Take off your right shoe and drive in your sock,barefoot or very thin soled shoes so you feel the pressure on the gas pedal.Drive with a "feather foot",barely touching the gas pedal enough to keep your speed.Let the car slow down going uphill (don't move the pedal) and speed up going downhill if traffic permits.A light touch will give better results than a cruise control but it will aggravate anyone behind you.If you can pulse and glide you may get better results yet.Mostly it will depend on traffic, the slower (45-50 mph) the better.

[gabe1475]

Originally Posted by rfernatt

- Different engine oil that improves mileage (I don't recall the special fuel efficiency rating), but you have to go to 5W-30 I think as it's not available in 0W-40

Can you use this without voiding the warranty? Or is this one approved by smart?