Ok guys ... after running two more full tanks .. it was obvious that my gas mileage was just simply shot. As I mentioned in the beginning, I lost about 60 miles to the tank. Well what I went ahead and did was I took off the 18" OZs and put back on the stock Mazda rims. And what do ya know .... my mileage went right back up where it was before. So the heavy a$$ OZ rims were giving me problems, but it doesn't make sense because when I first put them on, I had no problem but it was only after about 4 full tanks that I started to notice a difference. Strange huh? But at least I'm not losing tons of cash on gas anymore.

 

i dont think i've ever gotten 30mpg's out of my p5....ever....28mpg is my best so far and it's RARE to get that.

 

Same here ... but for a while there I was gettin low 20s so about 28 is much better.

 

I think eddiejoe56 hit the nail on the head, back to basics. Bad or plugged air filters are often over looked. The trouble light check isn't bad, but don't take it as gospel. On our hobbie stock car we fought a problem with how it ran and it consumed fuel like crazy. A visual check it (air filter) looked good, but we were desperate (3 carbs, tore motor down, plugs, wires, etc.) so we preplace the air filter with the "AIR HOG" and it ran like a chap. I can't believe that your tire change has created that much more surface area to kill your mileage.

Good Luck

 

hahhah oh god, you know how many times I look at the care in front of me and I see one wheel or both wheels are flat, I must say to the average car owner really does not take care of the tire preesure, a loss there can drastically effect fuel economy, I guess the same can be said for 1 or 2 year old air filters in dirty areas .

so those two items i would bump up to the top of the list. but they are all important as eddie itemizes

 

yeah, I always try to run 36psi or so in my tires (stock dunlops) unless I'm at the drag strip...then it's 18psi!

 

Absolutely AGREE!

I've had a bad mpg with my Mazda... tried the usual to improve it (new airfilter, injector cleaner, tested for brake binding-none... etc)... I was still getting about 280 mpg (Using Imperial gallons 1Gal = 4.55L !) ...

I used to have 30 psi air pressure in all tyres ... I took that up to 35 psi... and VOILA ... The Mazda pulls better and I get 300+ mpg

PS: my Mazda is an AUTO,.... 1.5 petrol engine ... The tyres are the original stock tyres which came on the Mazda from Japan (175/70R13).

The recommended tyre pressure by the Japs is on a sticker usually the door rim... see photo!

 

Funny...that's what I was thinking.

I'm just used to my little 4-banger not getting very good gas mileage I guess. At least I have the Miata, it still gets pretty good mileage if you keep your foot out of it!

 

I get about 350-400 miles to a tank. I have 17" volks, an AEM short ram, and a RB axle back. I must say that the Royal Purple Oil I run, is credited for the improved gas milage. It is a bit more expensive(about $70 a case), but I figure I am saving money in the long run.

 

Whoa whoa whoa ... 350-400 per tank? Are you driving a Festiva or somethin? Cuz if you got an MP5 and you're not full of crap ... I'm investing in some oil then.

 

You know that when the low fuel light comes on, there is a lot of gas left in the tank, right? Like two and a half gallons? It's a crazy amount. I fill up when the check fuel light comes on, and it works out to about twelve gallons. The tank holds 14 (or was it 14.5?). That would put you at a probable mileage of 378 per 14 gallons, at 27mpg mixed city/ highway driving. Better go invest in some oil.

 

I am consistantly getting 30+MPG outta' the P5... Even with the wider tires/stock rims... And i hit it hard - no limp foot here...

huh.

 

I am tellin you, 350-400 a tank. 02 P5.... I am sure it is more on strictly highway, but I havent taken a road trip in quite some time, so i am not sure. My daily drive is about a 50/50 split highway and city.

 

Well I guess I didn't know that there was around two or more gallons left when the light comes on, which would put me at about 340 miles per tank. The reason I was gettin crappy mileage at first is because of the rims, no doubt about it. They're 18" OZs and they are HEAVY! And our cars (MP5) don't really have all that much ***** so it would make sense that the car was struggling when taking off. I probably gained mileage on the highway because the bigger wheels build up more momentum and keep rolling easier, but I'm sure it was killing me on city driving because they're harder to get going, especially by our pansy a$$ cars. I also custom rigged a K&N filter, no CAI yet but it's coming, and got it all cleaned and oiled up, which kinda helped in both performance and gas mileage too. But as far as the oil goes, if it'll really make a difference, what kind should I get? Someone mentioned some Purple somethin Oil ... is that what everyone agrees on and why?

 

My wife's new 2.3L hatch gets an average of 24-26mpg in city driving....just back and forth from school to home. I was a little upset but the car is so damn nice it's hard to be upset about mileage!