Recent fuel economy changes

[zmzmzm]

I installed an eBay SRI a few weeks ago, and thought I'd share some info about the gains I experienced. The total cost for the SRI was $45. I installed it myself in about 45 minutes. I've run three tanks of gas since the install, and kept track of fuel mileage for the latter two - the first tank wasn't full when I installed the SRI, so I didn't bother to calculate fuel economy. The first full tank of fuel I ran with the SRI (other mods, by the way, are Kartboy shifter bushings and synthetic fluids) was on 88 octane fuel and netted 33.89 mpg on mixed driving - some with me, some with my wife, some on the highway and some in town. The second full talk of fuel was on 85 octane fuel and netted 32.95 mpg on mixed driving - some with me, some with my wife, some on the highway and some in town. Given the current cost of fuel, the SRI will pay for itself within about 4 months - we drive about 2,000 miles per month.

So for you cheap people out there - like me The eBay SRI is a simple mod that will pay for itself quickly. And it sounds fantastic!

And before anybody responds, let me say this - I don't care if I lost or gained horsepower, I don't care if I lost or gained torque, I don't care about heat soak at idle, I don't care about acceleration improvements and I don't care that my SRI didn't come with a fancy brand name. It works, and I like it.

I hope some of you find this useful.

Chris

 

[lasermp5]

nice....

 

[SciFiMan]

I wish my wife could drive stick so I didn't have the auto. I'm getting 27.5 mpg consistently, and that is with using cruise for about half of my daily 85 mile drive. $2.14 for 87 octane around western Chicago burbs. Will probably go up again any second now.

 

[+ friction]

That is some awesome mpg. Just how loud is the Ebay SRI, anyway?

 

[FLSilverP5]

how does it sound, cuz i bought the cold air intake off ebay for $63 shipped. i havent noticed and significant increases but then again i dont keep that great of track. what is the main different between sri and cai?

 

[Poseur]

SRI= Short Ram Intake meanng it's inside the engine compartment, generally in a similar location to the stock airbox. CAI= Cold Air Intake your filter is re-located to somewhere away form the engine's heat where it gets cooler air. In our cars this is almost always in the bumper infront of the driver's side front wheel. IT's a handly little pocket that, if you look at it, appears as though it was just about MADE for the things...

Nowthen for advantages. SRI's are smaller, less parts, less hassle to get to the filter element, and less expensive. CAI's are that cooler air is denser and contains more oxygen which allows for more compete combustion, as wel as keeping general temps down which is good. One thing to watch for, though isthat some claim that the piping itself geting heated up by the engine compartment will actually warm that cool air befor eit gets to your engine, so some will heat-tape wrap the piping...

 

[zmzmzm]

With normal driving; shifting at 3500 or so, not too heavy on the throttle, I can't notice any increase in sound with the SRI. If I dip the throttle deeper or hold the RPMs up past 3500, then I notice the extra throat from the intake. It really is an ideal mod for me - cheap, simple, effective, there when I want it and invisible when I don't.

A CAI will not make as much of a difference in sound from what I've heard here. I don't know how long it would take to pay for itself, either, or if there are significant fuel economy increases with it over the SRI.

Of course, if you're more interested in power and acceleration increases, why did you buy a Protege in the first place? Nah, just kidding... but I'm far more interested in generating a few more mpg than I am a few more hp. Maybe I'll call it a wallet dyno over a butt dyno sort of situation. And you'll always notice the wallet dyno!

Chris

 

[kid prodigy]

I get 400 miles with my injen cai, but when I had my stock on, I got around 325-350 on full tank. I've always used 91 octane cause I've noticed that when I used a lower octance, I got less milage.

 

[sgryzko]

I installed an eBay SRI a few weeks ago, and thought I'd share some info about the gains I experienced. The total cost for the SRI was $45. I installed it myself in about 45 minutes. I've run three tanks of gas since the install, and kept track of fuel mileage for the latter two - the first tank wasn't full when I installed the SRI, so I didn't bother to calculate fuel economy. The first full tank of fuel I ran with the SRI (other mods, by the way, are Kartboy shifter bushings and synthetic fluids) was on 88 octane fuel and netted 33.89 mpg on mixed driving - some with me, some with my wife, some on the highway and some in town. The second full talk of fuel was on 85 octane fuel and netted 32.95 mpg on mixed driving - some with me, some with my wife, some on the highway and some in town. Given the current cost of fuel, the SRI will pay for itself within about 4 months - we drive about 2,000 miles per month.

So for you cheap people out there - like me The eBay SRI is a simple mod that will pay for itself quickly. And it sounds fantastic!

And before anybody responds, let me say this - I don't care if I lost or gained horsepower, I don't care if I lost or gained torque, I don't care about heat soak at idle, I don't care about acceleration improvements and I don't care that my SRI didn't come with a fancy brand name. It works, and I like it.

I hope some of you find this useful.

Chris

Thanks for the info man!(boom05) I've been thinking about getting an intake (either CAI or SRI) but Ive never heard any real numbers until now. I dont trust ebay that much so if i do get an intake, it will probably take longer to pay itself off.
But now with the gas prices reaching ridiculous heights, I want to do anything to increase my mileage.

 

[zmzmzm]

I get 400 miles with my injen cai, but when I had my stock on, I got around 325-350 on full tank. I've always used 91 octane cause I've noticed that when I used a lower octance, I got less milage.

I've never tried it with my Mazda, but 91 octane will probably yield higher fuel economy than 87 octane. It will not be worth the price difference, however, so even though you may buy a little less fuel, you'll definitely spend more money.

And a little pet peeve of mine: fuel economy is only measured by miles per gallon (mpg) or kilometers per gallon (kpg). Miles per tank isn't a fuel economy measurement, it's just a ballpark sort of blindfolded dart throw. The only way to accurately calculate fuel economy is by dividing the number of miles driven after a fillup by the number of gallons used to refill the tank. And the more precise you can be, the better idea you'll have of any actual gains.

 

[+ friction]

And a little pet peeve of mine: fuel economy is only measured by miles per gallon (mpg) or kilometers per gallon (kpg). Miles per tank isn't a fuel economy measurement, it's just a ballpark sort of blindfolded dart throw. The only way to accurately calculate fuel economy is by dividing the number of miles driven after a fillup by the number of gallons used to refill the tank. And the more precise you can be, the better idea you'll have of any actual gains.

I second that: an H2 can get up to 448 miles on a tank of fuel (14mpg on the highway times a fuel capacity of 32 gallons). But still, everyone here is talking about only P5's (or should be, at least) so it is somewhat relevant.

 

[protegeV]

yeah, that is some crrrrrrazy fuel economy u got there.

Im getting between 23 and 27mpg with a 5spd.

 

[Poseur]

A note on the octane bit. Lower octane=more btu's=more efficency&power. Unless your engine is tuned more aggressively higher octane is shooting yourself in the foot. Octane is resistance to knocking, and that's it. Basicaly it means the fuel is harder to burn. Race cars use higher octane, yes, but they're tuned much more aggressively than anything streetable. Hell I'd run 80 octane if I could get it and it didn't knock.