I drive a 1999 cavi with 2.2 engine and auto tranny 128,000 miles. The best mpg i can get driving like a grandma is 27 mpg combined city and highway. I have done a tune-up with in the last 1000 miles. are there any performance mods I can do to the car to get better mpg? thanks!! Ben
There is plenty you can do, but whether the results are 100% cost effective is up to you.
Things that take restriction from your air intake and exhaust will increase performance, gas milage, and noise.
Things like Tornados, fual line magnets, and other gimmiks do
NOT increase anything, just decrease the amount of cash in your wallet.
You can also look into things like aerodynamics...especially if you do a lot of highway driving.
clean air filter, plugs, make sure your o2 sensor is good.
~1996 Cavalier LS 2.4L (auto)
There arent really any modifications that will "pay for themselves" in milage returns. That said, there is a lot you can do with HPT and a wideband in terms of performance and mpg.
Stock exhaust is1-7/8". an upgrade to 2" alone with a good chambered-style muffler after the cat is the way to go, maybe even with a resonator between the cat & the first turn by the rear axle just to get the "tinny" sound out of the note. Makes it a nice, quiet bassy tone.
Making a Fresh-Air system certainly makes a difference, especially after you've done the exhaust. Remember: The more smoothly & directly the air flows from the filter case to the throttle-body, the better.
MSD's DIS-2 ignition system: The complete set with the 8224 coils, the box, the adapters for the bow to interface with the ICM & coils, the Super-Conductor wires & a set of durable plugs gapped to stock specs will make a night-&-day difference. How much so? I ran an MSD system on my '88 Dodge full-size sport-ute (Ramcharger) that had a TBI 5.2L V-8 with Champion truck plugs gapped to stock specs, and got a 20% improvement in mileage. You may get more since you have Sequential Multi-point on a OBD-II system. Does that sound good, or what?
A header with long primaries or a 4-2-1 (Tri-Y) style with the exhaust help greatly since it help scavenge the spent fumes from the cylinders. The Tri-Y is considered more desirable since it makes improvements across the RPM band to give a higher, broad torque curve. And better torque (Especially down low, like a diesel has) is what makes better mileage.
The rocker conversion: Search here & you can read all about it. This with the stock cam will help make the engine more of a stump-puller (Like a diesel!) by increasing low-end torque. And better low-end torque will help you get going from even a stop without so much throttle.
All this combined will help you get better mileage, although I can only guess how much (30+mpg, maybe?). It all depends on what all you do, and how you drive after you've done it. I wish you luck in your endevour, man, as I have the same goal in mind with my '99 Sonoma, which has the same engine with just a different manifolds for it's application in the truck.
Oh, feel free to play around with the octane of fuel you run in it. For some crazy reason our engine likes 93, although you'd think by the way it's all put together it'd be just fine with 87. Go figure...
Go beyond the "bolt-on".
After talking about this on another post about tuning, I thought I would add it here also.
Tuning seems to be the best way to add to a motor's fuel efficiency.
See if Trifecta will do a canned tune for your 1999 2.2 Cavi.
All you do is order the tune, take the GT tuner and plug in under your dash and hit download.
It takes 10 minutes and your retune will give you a few more horses and much better mpgs.
On a Cobalt it added a lot more miles per gallon, and I would be happy at even half the results they got for the $250 they charge plus shipping and return shipping which is $46.
2003 Sunfire with a 2 1/4 inch turbo muffler, 2 1/4 piping to a 2 1/2 inch resonator (bigger to make up for the baffling), a 2 1/4 inch catalytic converter, 2 1/4 inch down-pipe, a ported LSJ manifold, a drop in K&N filtercharger and sports a Bomber body kit with a VIS Invader hood.
Hmmmm... That seems like a good way to go with my '99 Sonoma, since I'm looking to get as many miles as I can outta every drop. And be able to enjoy driving while doing it!
Go beyond the "bolt-on".
