Honestly, I don't know much about the 2.2. I know it's an OHV, pushrod engine, with a 3 speed auto (sadly it's not a manual transmission, that would make it a bit more fun). From what I've read in the newbie section there are two (?) different variations between the S10 and the Cavy line. Changes occurred during the 1996 and onward years between the Cavy 2.2.
Anyway, let's get on with it shall we? This'll be my daily driver to conserve gas for my weekend/summer driver. Besides swapping in the manual transmission, as I'm looking to put the least amount of aftermarket support into the engine/trans./body as possible, I'm going with the free mods and the usual upgrades to increase MPG.
First and foremost, the steps to be taken will be in the maintenance section. Remember though, I'm looking for MPG, not horsepower/torque numbers. 40+ is attainable, 300 WHP with this engine and trans., financially, is not.
Besides maintenance which includes tie rods, full tune up (spark plugs, wires, fuel filter, air filter), serpentine belt, tire rotation, brakes all around, and an oil change, there's not too much. Which I'm not surprised by. I've worked on these cars before, though not the 2.2 in specific, more along the lines of the ECO (which I give props to a as a great N/A engine), but not so much the 2.2 OHV.
The plan is to reach high 30s MPG or low 40s MPG. To do this I'm going the normal upgrade path of I/H/E. Freeing up the restrictions is usually the path to go in reaching attainable numbers. The intake, as budget is concerned, will have to be custom fabricated from spare intercooler piping, extra AEM air filter, and a few silicon couplers. It will, hopefully, be a true CAI or an SRI with an air filter heat shield and some header wrap/house ducting wrap for the intake pipe itself. I may go ahead and port and polish the throttle body along with 'sharpening' the throttle plate itself allowing for smoother airflow.
The ignition will consist of NGK iridiums gapped a tad larger at .062 and run-of-the-mill wires. Fuel filter will be OE from RockAuto. Oil will consist of Valvoline 5W-30 half synthetic for the time being until I know how the bottom end is. No bearing shavings as of yet, but with 164k on the clock there's no telling how good the bottom end is without taking the oil pan off and finding the tolerances of the gaps between the bearings and the crank; not something I have time for or really want to do on my one day off a week. If the internals prove alright without any knocking, full synthetic AMSOil will be going in at a weight of 5W-30. I may risk an AMSOil 5W-20 for the winter.
Weight is always one of the big things in running MPG as it is with 1/4 mile times, so let's shed some pounds on this car. I'll begin by removing the rear seats, trunk components (minus the spare and the OE jack). Good thing this is a coupe as usually they run lighter than saloons which I'm hoping is the case with the Cavy.
Fuel will be run with standard 87 octane seeing as there's really no way to adjust spark, whether advanced or retard and the possibility of a straight OBD2 ECU. SeaFoam will be run through the engine after the intake manifold has been taken off and cleaned thoroughly.
Tire pressure'll be run to 34 pounds constant at cold temperature; 4 PSi above factory recommendations. Compensating for the wider tires that are on the car (205 versus 195?). Lack of weight will certainly help off-set the increase in tire pressure, especially in the rear.
Given there're no huge options on the car (no power anything except steering, no A/C), I don't have much to worry about in terms of removing pulleys and finding smaller belts unless I don't want power steering, which is nice to have as a DD.
Cooling system will be dealt with via Water Wetter added and possibly a lower temperature thermostat. The OE is what, 195*? I'm looking to add a 180*, though I'm not sure how it would perform with the possible OBD1/2 hybrid or full OBD2 ECU. I'm not worried about it throwing a code, just the matter of time of swapping out the thermostat again.
Have I bored you yet?

Any input is much appreciated. I know there are free mods for every car, quick fixes, etc., but since I know DSMs more than I do the Cavy, any help is much appreciated.

Here we go...
0) Major change for the 2.2L was in '98. '96 was just an ECU change.
1/2) Change your timing chain and tensioner.
1) Just a 5-speed swap can get you to 40mpg with very conservative driving.
2) It's your daily, and you seem to be trying to save $$$, so why waste your $$$ on synthetic?
3) For MPG, you want a WAI, not a CAI. DO NOT use 3" piping (you didn't specify).
4) Similarly, for MPG, DO NOT use a colder thermostat. If you're going to use water wetter, try to find a higher t-stat even.
5) You can tune with Megasquirt just as easily as on a DSM. Since you have a '95, you shouldn't even need to worry about emissions issues.
6) Zero-deck the block if you ever take it out.
7) Iridiums are just more $$ that is better spent elsewhere. Grab some MSD coils if you really want to run a wider gap.
8) Skinny tires would be better, wider is worse...
9) 4-2-1 header if you do mostly city driving, 4-1 if you do mostly highway. Get a high-flow cat, and keep your piping 2-1/4" or smaller




fortune cookie say: better a delay than a disaster