MetroMPG.com mailbag: Which Metro mods to do first - best return on investment

[MetroMPG]

Got this e-mail from a visitor to metrompg.com ....

Love.the site. Been reading a lot of forums and have some questions. Basicly which mods to do first to save money. So the more they cost the long it will take to recope the cost
tell me what you think.

• 200mph tape to make front bumper more areo $7
• xfi cam grind $80
• 1 inch spring lowering
• 25% underdrive pulley
• Pizza pan smooth wheel covers $20
• rear wheel fender skirts $40-100

right now i get 40-48mpg depending on freestyle driving or don't smash the rottin egg under the gas pedel. Ave 45mpg . would like to get closer to 55-60mpg

Bang for your buck:

Biggest savings will come from driving techique, and a fuel economy gauge is the best way to hone your techniques. Get an MPGuino if your car is pre-1996, or ScanGauge or equivalent if it's after 1996. (You can always re-sell the gauge in 6 months or so once you've used it to develop best habits.)

You missed: Engine kill switch $4. Stop idling. Stop running the engine while coasting up to turns/stops. Will save you a pile of fuel in sub/urban driving (see Coasting experiment: engine off VS. engine idling - MetroMPG.com )

Each of the other mods you list will save you roughly a few percent each, so ~12% total if you do them all. If return on your investment is your primary concern, just do the free/cheapest ones first.

But there's much more you can do than you listed.

See our list of 65+ Efficiency Mods and 100+ Hypermiling Tips

You can see my list of mods on my Firefly: Firefly efficiency mods - MetroMPG.com

[ATaylorRacing]

On my 96 Geo 3 banger NO simple mods to the motor made any improvement at all on mpg or even 1/4 mile ETs. When bought the base timing was already bumped up 2 degrees so I never messed with that. A borrowed K & N made the car get WORSE mpgs, and no AF made it worse yet! The only things that I did that made it get better mpg AND run quicker in the 1/4 mile was to remove 140 lbs, make headlight covers (did not have the newer aero lights on it, and make a grill block. I used this car to deliver rim/tire packages that I deliver and every 100 lbs was worth a full mpg at 55-60 mph. I never tested the aero mods difference, but they made the top speed raise from only 81 to a decent 89! The aero mods did not make the 19.90 at 65 mph 1/4 mile times improve. The 140 lbs DID make a difference...once added back on the 19.9 ETs fell to miserable 20.5s and the car was not allowed to race since the track had a 19.99 minlike most NHRA tracks do. The stick shift series I race in changed their low end cut off to 17.99...that and the fact that the wife refused to ride in it AND the 95 Neon has AC and 4 doors is the reason I sold the Geo last fall. The guy that bought it drives 240-280 miles per day for his job...his F150 was using a full tank of gas a day and the Geo gets three times the mpgs....he called to say he was saving about $150 every three days now and it MUST be even more savings now with gas going through the roof. BTW, my wifes 12-14 mpg in town minivan was replaced with a (so far) 42-53 mpg Prius...basically the mpg difference from the van to the Prius is paying for all of the payments except for about $50. If prices keep going up the mpg difference between the two will make the Prius pay for itself!