Mazda 5 GT Poor Fuel Economy Help!

[mpvue]

when you ask a dealer to check if anythings wrong, because of the mpgs, they tend to just roll their eyes. because, if they don't have any codes show up, there is nothing else they can do/know how to do. if it runs well, is idling, accelerates properly, it is ok by them.
bad gas/bad pump is a possibility; though, pumps are 'supposed' to be audited by the county/township and have a sticker. winter blend gas is also a culprit, don't know when it's switched out.

 

[AIMWO4]

Install a Dashhawk and analyze the numbers if you have the $$.

 

[5zoom]

I get about 255-275 miles at the 1/4 tank level based on 30/70 city/hwy out of my 08 5AT. I've taken mine past 400 miles a few times. I think practical range on the hwy, assuming no more than 75mph is about 425-450 miles. I'd like to see someone get 500+ miles out of tank, as I know it might be possible at 55-65mph.

I've got over 49k miles on mine now and the mileage seems a little better than when it was new.

 

[KBrian]

I'd like to see someone get 500+ miles out of tank, as I know it might be possible at 55-65mph.

Have a look at the thread "how far on a tank" in the welcome/lounge area.

Some (seemingly valid) claims of more than 500 miles on a single fill, with fuel left in the tank.(drive)

 

[thaxman]

Just filled up tonite: 11.3 gal, 273 mi: 273/11.2= 24.1 mpg all city w/stoplights every 1/2 to 1 mile. But then, since cruising @ 50 mph ~ 2K on the tach... by comparison, last 2 trips 240 mi 1-way in I-8 yielded 24-25 mpg since the tach was always hovering @ 4K.

BTW, the Volvo (2.3L turbo, 3600 lbs) has become the road trip car of choice b/c it cruises closer to 3200 rpm, so I am seeing hwy mpgs of 26-27 even with the weight penalty.

But that's the MT. I would expect the new 5AT to be MUCH better on the hwy.....(confused) (scratch)

 

[Tsuru]

On my last tank I managed to get just over 28 MPG (416.8 miles, 14.7 gallons) and that was approximately 50/50 city/hwy.
I have a question though, at what RPM does the VVT kick in? I've heard somewhere that it's around 3,300 RPM but that's only from one source. I know how easy it is to ramp the RPM's up, even while driving conservatively. While that may not be the total cause of your MPG woes it could certainly contribute.

 

[njaremka]

On my last tank I managed to get just over 28 MPG (416.8 miles, 14.7 gallons) and that was approximately 50/50 city/hwy.
I have a question though, at what RPM does the VVT kick in? I've heard somewhere that it's around 3,300 RPM but that's only from one source. I know how easy it is to ramp the RPM's up, even while driving conservatively. While that may not be the total cause of your MPG woes it could certainly contribute.

these engines have VVT? learn something new every day, if they do. VVT is continuously adjustable, not rpm set-point like VTEC.

 

[mars1100]

BallLightning:

We are getting over 300 miles per tank from what I have seen, I can't be exact because my wife does not give the car a break long enough for me to check and she always forgets to reset the miles.

Here are some other simple suggestions I have not seen offered yet---

Have you tried a simple bottle of the fuel and emmission system cleaner that the dealer charges you for but sometimes forgets to put in when you go for service?

I still take our 5 in for oil changes but purchase the fuel system cleaner from Mazda and pour it in myself.

You may want to make sure(question them) the dealer is using 5w20 oil and not 5w30, you never know what you are getting in that bulk oil.(this may affect mileage)

are you driving over 45mph with windows open?

 

[was98strat]

On my last tank I managed to get just over 28 MPG (416.8 miles, 14.7 gallons) and that was approximately 50/50 city/hwy.
I have a question though, at what RPM does the VVT kick in? I've heard somewhere that it's around 3,300 RPM but that's only from one source. I know how easy it is to ramp the RPM's up, even while driving conservatively. While that may not be the total cause of your MPG woes it could certainly contribute.

The VVT kicks in around 3300rpm. You can feel it if you creep the RPM's up slowly, when it hits 3300 it feels like you've floored it even though you haven't moved the accelerator at all!!!

 

[KBrian]

when it hits 3300 it feels like you've floored it !!!

What was98 said!(mswerd)

 

[gumball]

Install a Dashhawk and analyze the numbers if you have the $$.

I would just sign up over at www.fueleconomy.gov and use it regularly.

looking at my records over there I see I have never put in more than 14 gallons on a fillup and that's with the light on for a couple days and me worrying I'd run outta gas. My worst mileage has been around 16 or 17mpg where I suspected the pump may have been fraudulent (not an uncommon occurrence, BTW) and so I almost never fill up at the same place twice.

I find that based on my records over there over about 40 or so fillups I find the EPA numbers to be very close to spot-on. 21/27, 23 combined. I've gotten max of 30 on HWY and worst was 16 or 17 CTY, combined around 22 to 23.

 

[twintrbo]

It seems the tank is not a normal shape either since it seems to run out of fuel at varying rates. My first 1/4 got 80 miles but now Im half full at 130 mi. So looks like I'm aiming for another 260 mile tank, which means 20mpg if I fill up when the light comes on, roughly 13.1-13.2 gallons. Not horrible, but it seems to get mileage on par with much more powerful engines. I cant wait to take a road trip and get a 400mi run out of her though, I would feel much better about it! I only do about 5000mi per year so economy was not on the top of my list but I know that fuel wont stay cheap forever and I really dont like big lumbering vehicles as a matter of principle.

 

[AIMWO4]

Wasn't referring to those numbers. My mileage is posted there, too. I was referring to data points like commanding A/F, etc.

I would just sign up over at www.fueleconomy.gov and use it regularly.

looking at my records over there I see I have never put in more than 14 gallons on a fillup and that's with the light on for a couple days and me worrying I'd run outta gas. My worst mileage has been around 16 or 17mpg where I suspected the pump may have been fraudulent (not an uncommon occurrence, BTW) and so I almost never fill up at the same place twice.

I find that based on my records over there over about 40 or so fillups I find the EPA numbers to be very close to spot-on. 21/27, 23 combined. I've gotten max of 30 on HWY and worst was 16 or 17 CTY, combined around 22 to 23.

 

[AIMWO4]

I have had my 5 for over 3 years. I have discovered that the tank can't be completely filled, if the car is at an angle to where the lowest point is the filler tube towards the pump. This has led to a few strange numbers form every second tank during a short experiment I performed.

It seems the tank is not a normal shape either since it seems to run out of fuel at varying rates. My first 1/4 got 80 miles but now Im half full at 130 mi. So looks like I'm aiming for another 260 mile tank, which means 20mpg if I fill up when the light comes on, roughly 13.1-13.2 gallons. Not horrible, but it seems to get mileage on par with much more powerful engines. I cant wait to take a road trip and get a 400mi run out of her though, I would feel much better about it! I only do about 5000mi per year so economy was not on the top of my list but I know that fuel wont stay cheap forever and I really dont like big lumbering vehicles as a matter of principle.

 

[twintrbo]

I have had my 5 for over 3 years. I have discovered that the tank can't be completely filled, if the car is at an angle to where the lowest point is the filler tube towards the pump. This has led to a few strange numbers form every second tank during a short experiment I performed.

Well sure, that makes total sense, there will be an air bubble up there that has no room to vent out. Or the fuel in the filler tube shuts off the pump before it can supply enough fuel to push the air out of the vent.

FWIW I took a trip yesterday and was curious so I filled up and set out. It was 110 mi total driving and I had around 3/4 tank left when I filled up today. The driving was about 90% clear highway averaging around 65 MPH, there was about 10% 2 lane hilly backroads using manual mode, stop and go traffic and my usual >10 mi all city commute this morning with one full throttle pass around a garbage truck. It was me, wife, 3yo and 6 month old with about 50 lbs of stuff.

The 4 gallon fill up gives me 27.5 MPG which I am very happy about! On the open road I'm sure it would be able to do really close to 30. I guess the 5 despite its small displacement, relatively low weight and small size really does not do too well in pure city driving. When I say pure city, I'm lucky to go 1/4 mile without accelerating and then coming to a dead stop and speeds never exceeding 30 mph. However, with under 2000 mi on the odometer I do expect MPG to pick up a little. So being only 2 MPG off the city rating, I really cant complain.

 

[v_tofu]

under 200 miles does seem pretty strange. Any update as to a fix?

Just recorded my first tank today and got around 24 mpg. This is city driving.

 

[twintrbo]

Update to my mileage, I only got 18 MPG on the last tank I will say that my driving most closely resembles cruising for a spot in the mall lot. Its pathetic how bad traffic is where I drive. Oh well.......

 

[thaxman]

Here's an update for me as well. I was forced to take the 5 on a 500 mi round trip road trip. In Yuma, AZ currently, and the 1st leg was 252 mi, 10 gal. Full house w/2 adults, a 9yr old, a 6 yr old, a 3 year old & a newborn and 2 days change of clothes. I estimate a total payload of 550 lbs. Of course, the 5AT off an '08 or later would do better because of its hwy gearing, but 25 mpg & a constant 80 mph, @ 3750 rpms isn't too shabby.

 

[1WICKED6]

Honestly, I've had the 5 for a year now. its got 45,000 miles on it ( its a used 2007 touring with the 4 speed auto) The first fill up was getting 27 miles per gallon but that was all highway...since then I've gotten bigger wheels and its been all city driving. ( I mean a stop sign at every frickin corner..Reading is ridiculous.) and I average 16-17mpg. I've noticed on highway driving that if I fill up I can squeeze up to 120 miles out of a 1/4 tank, if I'm driving in the city I barely squeeze out 70 miles.....My average tank is like 225-240 miles out of like 14gallons. Not stellar but my 2001 Rodeo 5speed was garnering 11-12MPG so it is an improvement for me.

 

[skyhawk]

I had an old '86 buick skyhawk 2-door 1.8L Turbo Automatic And that car had almost same milleage as the 2.3L Mazda5.

I initially thought the 'newer mazda5' would be better. But then the
engine is bigger. lolz.

- proof that the engine size is a main factor in milleage.

- also proof that I managed to keep that old buick in A1 condition.
(countless 'freedom weekend' spent in the garage 'tuning' the buick,
with friends and cold beers).

Average fill up of my Mazda5 is 50 or so liters. The km reading is about
400 to 450 km. I never reached 500km. on a full-tank. City driving.