Mazda3 Real World MPG

706 messages, Last post on Oct 19, 2009 at 9:04 AM

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What is this discussion about? Mazda MAZDA3, Mazda MAZDASPEED MAZDA3, Fuel Efficiency (MPG)

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#705 of 706 Re: 5 years of mileage data [vanquish421] by smoothsailin Oct 16, 2009 (2:20 pm)
Replying to: vanquish421 (Oct 15, 2009 10:03 pm) If you read my post again vanquish421 you'll see I was comparing the 2.0 L and 2.3 L engines-not the 2.0 vs. 2.5 L . The 2.5 L was not available when I purchased my '05 3i. I'm unfamiliar with corksport and have no idea if their figures are reliable, but since drivetrain power losses s/b similar between two Mazda 3 models I find the differences in crankshaft vs. "at the wheel" results for the two engines out of sync based on the figures you quoted. The 2.5 L is rated by Mazda at 167 hp and 168 lb/ft at the crank and Mazda's published specifications for the 2.0 L and 2.3 L engines models are as follows: 2.0 L: 148 bhp & 135 lbf•ft 2.3 L: 156 bhp & 150 lbf•ft 2.3 L MZR DISI Turbo: Mazdaspeed3: 263 bhp & 280 lbf•ft So the 2.3 L is rated for just 8 hp and 15 ft/lb more than the 2.0 L. My lawn mower puts out more than that! The 2.5 L of course does better with 19 hp and 33 lb/ft over the 2.0 L. A 19 hp advantage still is hardly earth-shattering, but I can understand how an additional 33 lb/ft could be enough to be appreciated in a small car like the 3. Of course, the 2010 modes ARE also heavier than first generation models too and from what I've read differences in real-world performance between '04-'09 2.3 L models and 2010 3s models w/the new 2.5 L engines are negligible. The figures you cited from corksport indicate the 2.0 L engine lost 30 hp and 25 lb/ft to driveline losses from engine to the front wheels, but the 2.5 L only lost 9 hp and 6 lb/ft? If so then either the 2.0 L may have been a poorly running example or the 2.5 L could have been a ringer since driveline losses between the two should have been similar (imo). From what I've read a 10%-12% loss from cranshaft to the wheels is fairly common. 148 hp x 10% = ~ 15 hp...which would result in 133 hp at the wheel for the 2.0 L 167 hp x 10% = 17 hp...which would leave 150 hp at the wheel for the 2.5 L So the corksport figures don't make sense. If anything, the 2.5 L should have lost more power from crankshaft to wheel vs. the 2.0 L...not less. In any case, when browsing the Mazda 3 forums I've read where real-world results have shown a stock 2.0 L mtx can produce n e.t within a 1/2 second of a stock 2.3 L mtx in the quarter. Of course differences in driver experience could easily make more difference than that. If bragging rights or racing for pinks is important to you a ½ second difference in the quarter or from 0-60 may be significant. But during my day-to-day commutes I could care less about a ½ second difference for rarely do I need maximum performance from my 3i's 2.0 L anyhow. However, when I have the 2.0 L has been more than powerful enough for my needs. I'd also like pit my 3i mtx against someone with an equally stock 3s w/the 2.3 L atx . If more than a car length separated us by the end of the quarter mile I'd be very surprised. In any case, if I wanted high performance in a 3 I'd bypass a 3s motivated by a normally aspirated 2.3 or 2.5 L engines and choose a Speed 3 anyhow. It all comes down to what's more important to you. For me, I'd rather pay 25% less at the pump for 99.9% of my driving in lieu of paying at the pump all the time just to have a hair more performance available for the other .1% when I may want to floor the pedal. Replies to this message: autonomous (Oct 19, 2009 9:04 am)
#706 of 706 Re: 5 years of mileage data [smoothsailin] by autonomous Oct 19, 2009 (9:04 am)
Replying to: smoothsailin (Oct 16, 2009 2:20 pm) It all comes down to what's more important to you. For me, I'd rather pay 25% less at the pump for 99.9% of my driving in lieu of paying at the pump all the time just to have a hair more performance available for the other .1% when I may want to floor the pedal. Well argued. You are not alone!

#705 of 706: Re: 5 years of mileage data [vanquish421] by smoothsailin; Oct 16, 2009 (2:20 pm)

Replying to: vanquish421 (Oct 15, 2009 10:03 pm)

If you read my post again vanquish421 you'll see I was comparing the 2.0 L and 2.3 L engines-not the 2.0 vs. 2.5 L . The 2.5 L was not available when I purchased my '05 3i.

I'm unfamiliar with corksport and have no idea if their figures are reliable, but since drivetrain power losses s/b similar between two Mazda 3 models I find the differences in crankshaft vs. "at the wheel" results for the two engines out of sync based on the figures you quoted. The 2.5 L is rated by Mazda at 167 hp and 168 lb/ft at the crank and Mazda's published specifications for the 2.0 L and 2.3 L engines models are as follows:

2.0 L: 148 bhp & 135 lbf•ft
2.3 L: 156 bhp & 150 lbf•ft
2.3 L MZR DISI Turbo: Mazdaspeed3: 263 bhp & 280 lbf•ft

So the 2.3 L is rated for just 8 hp and 15 ft/lb more than the 2.0 L. My lawn mower puts out more than that!

The 2.5 L of course does better with 19 hp and 33 lb/ft over the 2.0 L. A 19 hp advantage still is hardly earth-shattering, but I can understand how an additional 33 lb/ft could be enough to be appreciated in a small car like the 3. Of course, the 2010 modes ARE also heavier than first generation models too and from what I've read differences in real-world performance between '04-'09 2.3 L models and 2010 3s models w/the new 2.5 L engines are negligible.

The figures you cited from corksport indicate the 2.0 L engine lost 30 hp and 25 lb/ft to driveline losses from engine to the front wheels, but the 2.5 L only lost 9 hp and 6 lb/ft? If so then either the 2.0 L may have been a poorly running example or the 2.5 L could have been a ringer since driveline losses between the two should have been similar (imo). From what I've read a 10%-12% loss from cranshaft to the wheels is fairly common.

148 hp x 10% = ~ 15 hp...which would result in 133 hp at the wheel for the 2.0 L
167 hp x 10% = 17 hp...which would leave 150 hp at the wheel for the 2.5 L

So the corksport figures don't make sense. If anything, the 2.5 L should have lost more power from crankshaft to wheel vs. the 2.0 L...not less.

In any case, when browsing the Mazda 3 forums I've read where real-world results have shown a stock 2.0 L mtx can produce n e.t within a 1/2 second of a stock 2.3 L mtx in the quarter. Of course differences in driver experience could easily make more difference than that.

If bragging rights or racing for pinks is important to you a ½ second difference in the quarter or from 0-60 may be significant. But during my day-to-day commutes I could care less about a ½ second difference for rarely do I need maximum performance from my 3i's 2.0 L anyhow. However, when I have the 2.0 L has been more than powerful enough for my needs. I'd also like pit my 3i mtx against someone with an equally stock 3s w/the 2.3 L atx . If more than a car length separated us by the end of the quarter mile I'd be very surprised.

In any case, if I wanted high performance in a 3 I'd bypass a 3s motivated by a normally aspirated 2.3 or 2.5 L engines and choose a Speed 3 anyhow.

It all comes down to what's more important to you. For me, I'd rather pay 25% less at the pump for 99.9% of my driving in lieu of paying at the pump all the time just to have a hair more performance available for the other .1% when I may want to floor the pedal.

autonomous (Oct 19, 2009 9:04 am)

#706 of 706: Re: 5 years of mileage data [smoothsailin] by autonomous; Oct 19, 2009 (9:04 am)

Replying to: smoothsailin (Oct 16, 2009 2:20 pm)

It all comes down to what's more important to you. For me, I'd rather pay 25% less at the pump for 99.9% of my driving in lieu of paying at the pump all the time just to have a hair more performance available for the other .1% when I may want to floor the pedal.

Well argued. You are not alone!