Hi all,
So I've committed myself to getting better mpg's out of my car for about a hundred different reasons, but I'm still trying to learn how to really drive in the first place, so I don't really think any of that super-advanced hyper-miling stuff is for me. I am interested in learning my car's peak operating ranges for fuel economy, however, and I'm ready to do what it takes to start squeezing more mpg's out of my 2. I've also equipped myself with an Ultra-Gauge to get more real-time feedback while I'm driving.
I've been doing some serious lurking in forums like CleanMPG and Eco-Modder to learn as much as I can about driving efficiently, and have come back with plenty of information, but I'm honestly a bit more confused than when I started. The best information I picked up, however, was from looking at different BSFC maps and reading about engine efficiency and such. If I could see such a map for the 2, I think it'd really help me out since I do a lot of city-ish driving. I bought this car for the zoom-zoom, but I don't think there's any reason I shouldn't be able to zoom and still get good fuel economy.
That being said, here are some of the questions I still have about everything (most of them are aimed at using the Ultra-Gauge efficiently
1. Acceleration: Ive tried driving slow and forcing shifts (auto tranny) at low RPM's (2000-3000), and I've tried driving at a quick pace and shifting at higher RPM's (4000-5000). Driving a tank using each of these methods with ~80% city driving, I managed to get 25mpg for both methods (slow & short-shifting was 25.4, quick & high-shifting was 25.6). These were both measured using the built-in trip computer...is there really no difference? What have other members experienced?
My next step is to run the same tests with the UltraGauge, while monitoring other things like engine load, TPS, etc. However....
2. My UltraGauge's '% Engine Load' readout is a bit puzzling. Idle load is around 17% (A/C off.) 'Relative TPS' at idle is around 4%, which I've read is about right. Press on the gas, however, and the Engine Load shoots up to 100% almost immediately, even at a Relative TPS of only 10-15%. Any acceleration, quickly or slowly, puts the engine load in at least the 90's. Hit cruising speed (65mph) and it lowers itself to around 60-70%, and only drops below 50% during coast or idle. Is this right? Should I be looking at something beside Engine Load and Relative TPS in this car?
3. There are a few different fuel level gauges in the UltraGauge. However, we've determined that the built-in fuel gauge for the 2011 2 is inaccurate by a significant margin. Does that mean that all of the fuel gauges on the UltraGauge are also going to be inaccurate?
4. I had asked some questions regarding octane; Mazda recommends 87. On the UltraGauge, I can view Ignition Timing, and short term and long term fuel trims (STFT and LTFT.) Running a tank of 87, the Ignition Timing fluctuates anywhere from -7 during idle and deceleration, to ~45 while cruising. From what I understand, using a higher octane gas would remove the negative timing numbers, but not increase the positive timing numbers...is this correct?
5. For fuel trim, a positive number means there's more gas being injected, and a negative number means less gas being injected. My current fuel trims both run positive ranges from 0 on upward. Should I ever see negative fuel trim? Does any LTFT that's not 0 indicate a problem (positive or negative?)
6. What other gauges can/should I monitor to get the best instantaneous feedback while driving?
and finally,
7. Does anyone know where to obtain a BSFC map for this car? (longshot) Does anyone happen to have the BSFC map for this car? (even longer shot)
I really appreciate any comments, feedback and help that you guys can give me. Sorry for the long post, but I like to keep things condensed when I can. (Hopefully this isn't in the wrong forum!)
Thanks!
So I've committed myself to getting better mpg's out of my car for about a hundred different reasons, but I'm still trying to learn how to really drive in the first place, so I don't really think any of that super-advanced hyper-miling stuff is for me. I am interested in learning my car's peak operating ranges for fuel economy, however, and I'm ready to do what it takes to start squeezing more mpg's out of my 2. I've also equipped myself with an Ultra-Gauge to get more real-time feedback while I'm driving.
I've been doing some serious lurking in forums like CleanMPG and Eco-Modder to learn as much as I can about driving efficiently, and have come back with plenty of information, but I'm honestly a bit more confused than when I started. The best information I picked up, however, was from looking at different BSFC maps and reading about engine efficiency and such. If I could see such a map for the 2, I think it'd really help me out since I do a lot of city-ish driving. I bought this car for the zoom-zoom, but I don't think there's any reason I shouldn't be able to zoom and still get good fuel economy.
That being said, here are some of the questions I still have about everything (most of them are aimed at using the Ultra-Gauge efficiently
1. Acceleration: Ive tried driving slow and forcing shifts (auto tranny) at low RPM's (2000-3000), and I've tried driving at a quick pace and shifting at higher RPM's (4000-5000). Driving a tank using each of these methods with ~80% city driving, I managed to get 25mpg for both methods (slow & short-shifting was 25.4, quick & high-shifting was 25.6). These were both measured using the built-in trip computer...is there really no difference? What have other members experienced?
My next step is to run the same tests with the UltraGauge, while monitoring other things like engine load, TPS, etc. However....
2. My UltraGauge's '% Engine Load' readout is a bit puzzling. Idle load is around 17% (A/C off.) 'Relative TPS' at idle is around 4%, which I've read is about right. Press on the gas, however, and the Engine Load shoots up to 100% almost immediately, even at a Relative TPS of only 10-15%. Any acceleration, quickly or slowly, puts the engine load in at least the 90's. Hit cruising speed (65mph) and it lowers itself to around 60-70%, and only drops below 50% during coast or idle. Is this right? Should I be looking at something beside Engine Load and Relative TPS in this car?
3. There are a few different fuel level gauges in the UltraGauge. However, we've determined that the built-in fuel gauge for the 2011 2 is inaccurate by a significant margin. Does that mean that all of the fuel gauges on the UltraGauge are also going to be inaccurate?
4. I had asked some questions regarding octane; Mazda recommends 87. On the UltraGauge, I can view Ignition Timing, and short term and long term fuel trims (STFT and LTFT.) Running a tank of 87, the Ignition Timing fluctuates anywhere from -7 during idle and deceleration, to ~45 while cruising. From what I understand, using a higher octane gas would remove the negative timing numbers, but not increase the positive timing numbers...is this correct?
5. For fuel trim, a positive number means there's more gas being injected, and a negative number means less gas being injected. My current fuel trims both run positive ranges from 0 on upward. Should I ever see negative fuel trim? Does any LTFT that's not 0 indicate a problem (positive or negative?)
6. What other gauges can/should I monitor to get the best instantaneous feedback while driving?
and finally,
7. Does anyone know where to obtain a BSFC map for this car? (longshot) Does anyone happen to have the BSFC map for this car? (even longer shot)
I really appreciate any comments, feedback and help that you guys can give me. Sorry for the long post, but I like to keep things condensed when I can. (Hopefully this isn't in the wrong forum!)
Thanks!
