New Guy on the block

[sskooter90]

Hi, I'm somewhat new to the Eco-minded community, so I have a few questions. I have a 1991 Mazda 323 SE (hatchback) that I've driven for a year now; it's got a 1.6L 5-speed. It's all stock expect for an K&N repalcement filter and E3 spark plugs with 148,000 miles and weighs about 2500 lbs with me, spare tire, tool box and half fuel tank (used grain elevator scale). During the summer, I averaged 40 mpg and topped at 43 with it. I have Autometer gauges, tach, oil pressure, and voltmeter to monitor the engine (since the dash only has speedo, gas level, and water temp). I plan to buy a vacuum gauge to add to the cluster, do minor exterior modifications (such as partial boat-tail, front air dam, and rear tire covers; anything else?), weight reduction (rear seat and some interior trim) and a hot-air intake. Is there anybody out there who has done that to a 323?

Ok, now that the background is done.

I am running one size bigger tires on it; 185/70/13 vs. 175/70/13 (used to have a '86 Prelude, bought new tires, then died). I figured out that they are 2% bigger, so I think that they help with effiecency since I do a lot of highway driving (I add 2% of the miles to compensate). With your experiences, does this actually help?

On to the hot-air intake. I understand the dynamics of it. However, before I go on, I want to clarify some stuff. My major question is on the throttle position senser and mass air flow sensor. As we all know, the thottle blade will have to opened further to achieve the same horsepower to go the same speed. However, the throttle position senser, in theory, will compensate by dumping more fuel, due to the blade being opened further. Will this be a negative or positive net gain? Is there anything I can do to fool the sensor into thinking that the blade is at one position all the time (problem with that is idling)? Also, will the hot air have any effect on the mass air flow senser?

I am naturally a sceptic man, but I also wanted to ask about the supposely 'gas saver' things. Included is the Tornado and Turbinator intake inserts that supposely increase power and effiecencey. Any experiences with those? As I said before, I am very doubtful, but worth a question.

If there is anything more you want to suggest, be my guest, I'm open minded. I want the best fuel economy without sacraficing too much. Please help and thank you!