Poor Winter MPG

[diablo900t]

Hey guys,

This is my first winter with a Speed6. I've got a set of 17" performance winter tires on the car.

The past 2 tanks i've filled up have got 14 and 16 MPG respectively, which seems really poor.

I am starting the car some mornings to warm up, but no longer than 10 minutes, at most its 30 minutes total of warmup time inbetween tank fillups. All of my driving is city driving, but I usually get around 20-21 MPG

Should I be concerned?

 

[BOOSTR]

only if your plugs are still good, tire pressure is correct and the engine is otherwise healthy. seen a few of these threads on here latley. the ethanol blend reduces gas mileage slightly but not that much.

 

[CWPspeed3]

It depends on what area your in and what they do for the winter gas mix. I havent filled up enough to see the trend but I'm down 2-3mpg per tank of similar driving that I did all summer. Different tire sizes effect mileage as well but its probably the combo of winter gas and allowing the car to idle for 10min and taking longer to reach proper operating temperature. I wouldnt be worried unless that gas mileage is going to keep food off your table.

 

[diablo900t]

only if your plugs are still good, tire pressure is correct and the engine is otherwise healthy. seen a few of these threads on here latley. the ethanol blend reduces gas mileage slightly but not that much.

The car has only 5000 miles on it, and the tires are brand new. Granted, its a lot of start and stop driving, my commute to work is about 3-4 miles, but the gas mileage has been horrendous lately.

 

[fkmp5]

warming your car up ruins your gas mileage.. it's 0mpg constantly for up to 30 mins in your case.

if i warmed my car up for 10 mins each day before work (5 days/week) that's almost an hour wasted at 0mpg!!

i'm not saying warming you car up is a bad thing, just don't be shocked over dropped MPG per tank

i don't have a MS6 so I don't know this: do you have seat heaters? if so, try using the seat heaters to warm yourself and let the car warm up for about a minute instead of 10 minutes.. then see if your gas mileage comes up any.

 

[wannabe]

in both the cx7 and ms6 i have seen a drop of about 2mpg. i know my wife doesnt warm up the cx7 at all, and i only warm up the 6 for a minute or so. its the crappy ethanol.

 

[bova80]

i have also seen a drop in gas mileage....due to winter gasoline mix. could also be from your smaller than stock tires too.

 

[CWPspeed3]

in both the cx7 and ms6 i have seen a drop of about 2mpg. i know my wife doesnt warm up the cx7 at all, and i only warm up the 6 for a minute or so. its the crappy ethanol.

Ethanol will reduce fuel mileage but it is required by law to be stated on the pumps if there is ethanol in the gas and how much. It is not the only reason for fuel economy to go down I wont fill up at a station with ethanol but the winter blends and temps still reduce my mileage by 2mpg give or take. Turbo cars seem to drink gas when they arent warmed up to proper temps.

 

[BOOSTR]

I understand wanting to warm up a car in the winter but its not needed as the heat will start blowing warm enough within a few miles as long as the thermostat is functioning. Which in the OPs case it is as his engine only has 5k on it. Operating temp should be up then as well so boosting will be fine. Probably getting more than 10% ethanol in todays gas seeing how its added by the tankwagon driver upon delivery.

 

[wannabe]

Ethanol will reduce fuel mileage but it is required by law to be stated on the pumps if there is ethanol in the gas and how much. It is not the only reason for fuel economy to go down I wont fill up at a station with ethanol but the winter blends and temps still reduce my mileage by 2mpg give or take. Turbo cars seem to drink gas when they arent warmed up to proper temps.

yeah, all the stations say "up to 10% ethanol added"

 

[wannabe]

I understand wanting to warm up a car in the winter but its not needed as the heat will start blowing warm enough within a few miles as long as the thermostat is functioning. Which in the OPs case it is as his engine only has 5k on it. Operating temp should be up then as well so boosting will be fine. Probably getting more than 10% ethanol in todays gas seeing how its added by the tankwagon driver upon delivery.

its more for the engine than for the driver. cold oil doesn't flow as well, so its not recommended to get on it until its up to the normal range (120 degrees)

 

[MATT DAMOND]

Every car is going to get lower gas mileage in cold weather. You're car uses more gas when it's cold. The engine isn't working as efficient, like wannabe said the oil doesn't flow as well. Less efficient engine=poor mpg.
I am so pleased that gas is extremely cheap, I don't even care about mpg.

 

[Super Shredder]

at 33,000miles i've experience improved gas mileage from brand new, you can hear the stock bpv singing under 3000rpm now, and then just hoover vacuum intake whoosh for the rest of the rpm, i get a solid 26mpg and 20mpg right now, and i drive twisty mountain roads for 10miles to and from home multiple times a day, plus all the highway miles. driving slow in this car wont save you mpg, i beleive in using Direct Injection technology to take what it needs and save the rest, otherwise its just a regular dinkis 4 cyl hauling a 3800lb moose up the mountain. turbocharging = efficiency. USE IT. Let the computer do the gas saving.

 

[:: Gusto ::]

i usually get like 17.8mpg :: a couple times 18-19mpg.... :: recently 24mpg....

learn to drive outta boost!

 

[wannabe]

i actually got 32 mpg on my way home from work last night. i left at 3am, and took a route that normally would take me like 45 minutes at 40 mph at 7am when i normally leave, and didn't get stopped at a single traffic light. cruised at 40-45 in 6th gear the whole way home, made it home in 25 minutes.

 

[kalte]

Mine varies like mad...i did a 900 miles road trip recently and averaged 29mpg., going constantly about 70mph...i'm quite surprised,

Cause i've been getting 15mpg in city driving before my road trip, and i didn't even go into boost cause i live near to work (5 miles), so i take it really easy since it's crazy cold now.

I just installed the Cobb SRI too...

Edit: Forgotten to mention i check my tire pressures once in 2 weeks. Both front and back were set to 38psi cold.

 

[Super Shredder]

heavy car/no boost = bad gas mileage. heavy car/boost = good gas mileage. bypass valves only bypass when you use your turbo. ultra lean burn only makes a difference when there was a rich burn first. therefore, accelerate swiftly and end up in a high gear with low revs, dont use your weak 2.3 to lug your Moosedaspeed6 around, use the turbo, and use physics and active participation to save gas, not a 1950's housewife's reasoning.
yes, driving your Prius under 2500 RPMs and no more than 55mph will grant you maximum mpg. No, this does not apply to a Mazdaspeed6 2.3 direct injected awd 6spd turbo full size 4 door sedan.

 

[msp 2212]

do u got an intake cuz a cai on my speed killed gas and i live in utah where it should be around 7 tonight if u do just make a sri if not then i say get a beater cuz thats too nice of a car anyways u dont wanna kid to hit it do u lol....im sorry thats not funny

 

[Igve2shtz]

heavy car/no boost = bad gas mileage. heavy car/boost = good gas mileage.

I have to disagree. YES, it is true that the engine is MORE EFFICIENT under boost, but that is only in regards to specific fuel consumption, ie, lb of fuel per horsepower. Engines run better at higher RPM, and less intake restrictions (ie, a fully open throttle plate). Less restrictions lead to faster intake charges, which means more tumble in the air stream, more mixing of fuel, and allows more advanced spark for better power without knocking. On naturally aspirated cars, your philosophy works - More throttle increases efficiency

However, turbos are also THIRSTY. The engine is programmed to run a 11:1 A/F mixture under full boost, while at partial throttle the engine will run a 14.69:1 a/f ratio. The ECU dumps in a butt load of fuel when it see boost, and this WILL INCREASE your total fuel flow. Someone would have to sit here and do the data logs and integrations, but I am confident that partial throttle acceleration (no slow ass starts, but fast enough to keep up with traffic) will produce better MPG numbers than full throttle accelerations

But, with gas back down around $1.60/gallon for premium, who heck cares about MPG. I can now give it the gas again on every on ramp and not visualize some rich Texas oil man impersonating Scrooge McDuck swimming through a vault of my money.

 

[MATT DAMOND]

But, with gas back down around $1.60/gallon for premium, who heck cares about MPG. I can now give it the gas again on every on ramp and not visualize some rich Texas oil man impersonating Scrooge McDuck swimming through a vault of my money.

Amen!