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Mazda3 Real World MPG

961 messages,  Last post on Jul 27, 2012 at 1:44 AM

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

Messages Page 75 of 97

#740 of 961 Re: 3 months and 2500 miles... [roadburner] by shipo

Mar 20, 2010 (9:37 am)

Replying to: roadburner (Mar 20, 2010 9:21 am)
There's a guy that claims an improvement from 28 mpg to 34 mpg on a 2008 Mazda3 s Automatic over on the Mazda board that I frequent. I challenged him and he got nasty so I created a new thread over there called "CAIs and Fuel Economy; what's the real truth?" The thread garnered so much activity that it got "Stickied" to the top of the General Tech group.
 
I don't remember if it's still against the Rules of the Road to post links to other forums here in TownHall, so I sent you a PM with the links.
 
Best regards,
Shipo

#741 of 961 Re: 3 months and 2500 miles... [shipo] by roadburner

Mar 20, 2010 (8:08 pm)

Replying to: shipo (Mar 20, 2010 9:37 am)
There's a guy that claims an improvement from 28 mpg to 34 mpg on a 2008 Mazda3 s Automatic over on the Mazda board that I frequent.
 
The TH Jeep Liberty forum had a guy who made similar claims from simply using a K&N drop-in filter. I also called him on it and -big surprise- he called me an idiot. Things got really hysterical when a couple of gullible members bought K&Ns and then reported no change in their truck's fuel economy. He went so ballistic that he got banned and ALL of his posts on TH were deleted.

#742 of 961 Re: - [dudleyr] by igozoomzoom

Mar 21, 2010 (1:53 am)

Replying to: dudleyr (Mar 19, 2010 7:11 am)
When Mazda introduced the 2008.5 "refresh", the Canadian market got a base GX 5-door with the 2.0L engine. It was pretty basic in standard form (15" steel wheels, manual windows/locks, no rear spoiler) but they offered an option package that included power windows/locks, 15" alloys, and most basic convenience items. A/C was also optional.
 
The Canadian version of the 2010 Mazda3 also includes a 5-door GX model with the 2.0L engine. Power windows/locks are standard, but items like cruise control, steering wheel audio controls, side sill extensions, TCS/DSC, or even alloy wheels are not available. A/C remains optional on the GX, but it's standard on the two higher trim levels- GS and GT (along with the 2.5L engine).
 
I wish Mazda would offer a 2.0L Mazda3 5-door to the U.S. without sacrificing the sporty look (rear spoiler, side sill extensions, 17" alloy wheels). The fuel economy of the 2010 MZ3 i 4-door with the 5-speed automatic averages about 4mpg better than the 2.5L with 5AT and the performance is still decent (0-60 in 9.4sec). The 2.0L/5-speed manual combination has always been sprightly (0-60 in 8.6sec in the 2010) and returns over 30mpg average.
 
My 2006 MZ3 s 5-door (2.3L/5-speed manual) averages 24-25mpg overall and 90% of my driving is highway. I tend to drive around 75mph on the highway, which doesn't help. But I've also set the cruise at 65mph for a 200-mile trip and the trip computer showed 27.2mpg average.
 
I love my MZ3, don't get me wrong. But the Accord I had before it (2.4L 160hp and 5-speed manual) would cruise at 75-80mph on the interstate all day and never drop below 31-32mpg! And it was almost as quick, despite being a larger, heavier car....

#743 of 961 Re: - [igozoomzoom] by smoothsailin

Mar 21, 2010 (8:03 am)

Replying to: igozoomzoom (Mar 21, 2010 1:53 am)
I feel the difference in real-world fuel economy results obtainable by Mazda's 2.0 L vs. 2.3 L engines is greater than 4 mpg.
 
Four years ago due to a death in the family I made a relatively rare highway trip in my 3i from my home in Chesterfield VA to carry my Mom to Spartanburg SC in mid-February. As I recall I drove with the cruise control set at 70 mph for most the trip which was was almost all driven on I-95 and I-85. When I filled up in Spartanburg the result was 379.3 miles on 9.629 gallons for 39.39 mpg.
 
Note that the difference in our results is far greater than 4 mpg even though my average crusing speed was 70 mph, or 5 mph faster than the 65 mph you claim was driven for 200 miles in your 3s.
 
39.4 mpg - 27.2 mpg = 12.2 mpg difference
 
12.2/39.4 = a 31% improvement.
 
When I keep average cruising speeds in my 3i mtx around 65 mph in light winds results in the 41-42 mpg range are no problem, even more when I don't engage the cruise control. The cruise tends to tweak the throttle up and down almost constantly based on observations of throttle position sensor readings on my ScanGauge. I get better results when I forgo the cruise control and drive w/fairly steady pressure on the throttle.

#744 of 961 Re: - [smoothsailin] by smoothsailin

Mar 21, 2010 (2:03 pm)

Replying to: smoothsailin (Mar 21, 2010 8:03 am)
On second thought, an increase of 12.2 mpg above a 27.2 average represents a 45% improvement (12.2/27.2 = .4485).

#745 of 961 Re: - [smoothsailin] by smallcar1

Mar 25, 2010 (2:14 pm)

Replying to: smoothsailin (Mar 21, 2010 2:03 pm)
I rented both the 2010 3I and 3S. For very similar trips I filled up at the same pump at the same station (for both cars) and got 37 with the I and 33 with the S. These trips were almost identical 85% highway with no traffic and 15% city late at night with no traffic but lights and stop signs in Brooklyn.
 
I also picked up and dropped off the S in Manhattan. The S's trip computer, which I reset when I got the car, showed that I go 26.8 MPG in the 107 miles I drove the car. Subtracting the 72 miles where I measured the 33MPG means that I got 19 MPG during the other 35 miles which included driving on the streets of Manhattan and Brooklyn and going to some highway going from brooklyn to Manhattan.

#746 of 961 Re: - [smallcar1] by blueguydotcom

Mar 25, 2010 (8:38 pm)

Replying to: smallcar1 (Mar 25, 2010 2:14 pm)
Wow, that's horrendous. Mazda has a great chassis with the 3 (and I say that coming from BMWs and a Mini) but man they're really far behind when it comes to gearing and engine design. I can't understand how they still make a 2.5 liter that a) doesn't have 200 HP (like the ancient 2.4 liter engine in the TSX) and b) gets sub 30 MPG on the freeway cruising. Odd.

#747 of 961 Re: - [blueguydotcom] by smoothsailin

Mar 26, 2010 (5:07 am)

Replying to: blueguydotcom (Mar 25, 2010 8:38 pm)
Although Mazda's 2.0L and 2.3L engines apparently share a lot of parts, the larger engine is equipped with internal balance shafts. Cylinder bore dimensions for both engines are identical (the 2.3L has a longer stroke).
I've always wondered if the addition of balance shafts may increase internal friction and inertia considerably compared to the 2.0L which lacks this feature.
 
I filled up yesterday and the result was 551.1 miles / 12.882 gallons for 42.78 mpg.
 
Still glad I chose the 2.0 L and I wish Mazda would offer the same powertrain in the Mazda 5, 3i and 3s series with a six-speed manual.
 

#748 of 961 Re: - [blueguydotcom] by smallcar1

Mar 26, 2010 (9:21 am)

Replying to: blueguydotcom (Mar 25, 2010 8:38 pm)
On the part of the trip that was open highway I got 33 MPG with the S, with the I it was 37 MPG. It was not a bad tradeoff if one is more interested in the significant power increase of the 2.5.

#749 of 961 Re: - [smallcar1] by smoothsailin

Mar 26, 2010 (10:32 am)

Replying to: smallcar1 (Mar 26, 2010 9:21 am)
Agreed. However, if my primary reason for choosing an s over the i was performance, I'd probably pay the extra $$ for a MazdaSpeed 3. Based on what owners have reported, it seems to me that driven conservatively a Speed 3 may be almost as fuel-efficient as a normally-aspirated 3s with the 2.3 L or 2.5 L engines, yet performance-wise the Speed3 is in another league. Of course, if you must have an automatic transmission a MazdaSpeed 3 won't be an option.
 
I'll also submit my opinion that the ~4 mpg difference you cited for highway mileage results between 3i and 3s models may in fact be greater in mixed-driving conditions. Based on what I've read those who own a 3i don't seem to suffer as great a drop in mpg as do most 3s owners in city driving conditions.
 
In any case, how the cars are driven has the greatest effect on fuel economy. I've read reports from 3i owners who say they don't top 20 mpg for city driving in winter conditions. Contrastingly, over 5+ years I've never calculated a tank average under 32 mpg in my car and these days it's very rare for me to have one come in under 37 mpg. However, I know full well this would not be the case if I drove the car more aggressively and if I didn't conciously avoid taking short trips in it as much as possible.

Messages Page 75 of 97

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