Poor Winter MPG

[amp]

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

bad info... its the opposite..
plus one on what igve2shtz have already stated...
super..try boostin your car per given fillup and compare to what you can achieve without boost..

 

[Super Shredder]

i make sure every acceleration to speed limit has boost in it, i mean 3000-3400 rpm shifts, and then i go to high gear and low rpm, im not saying i boost all the time, i just dont waste time driving slow up until the road speed limit, i incorporate a short period of boost to get to proper speed and then i glide. im also taking about driving uphill becuase its around 5-10 miles of mountains i use to get home everyday, i dont allow the car to only use low rpm when accelerating, by using light boost instead of none, you circumvent the weight problems of driving upward or around town with many shifts. and on the highway i get to 6th gear as fast as i can. that doesnt mean redline it just means spirited short shifts. i've driven a regular 4 cyl mazda6 for a week as a complimentary rental, it gets terrible gas mileage in the mountains because it burns up all its gas busting its ass up the hills. MOOSEDASPEED6 is even heavier! AND its got an extra axle to spin. If we were talking wankel or na, you would be correct, but im talking about a DISI TURBO that weighs 3800lbs and needs boost, for a boost.

 

[Super Shredder]

otherwise you tell ME how i've never seen less that 20mpg EVER during my normal driving day. i must be doing something so wrong that beyond me, i make good gas mileage, and those who baby their rpms get 16mpg and are complaining about it? so i just shared how i shift and drive, to offer an alternative to pussyfooting based on a Prius's gas consumption rules.

 

[wannabe]

i have a scanguage that tells me my MPG realtime. the other day i left work early at 3am, and took surface streets instead of the freeway. normally i get 22-23 mpg on my drive home, in 6th gear at 70-75mph(about 3500 rpm). i got 32mpg in 6th gear at 40-45mph. thats approximately 2000 rpms, and not boosting. far better.

 

[OJ Bartley]

I've been watching my Scangauge more lately, with Super Shredder's comments in mind. I think he might be on to something, at least he is right about creeping back up to speed from below 2000 RPM or so, which sucks up a lot of gas. I watched while I was cruising in 6th, then had to coast because of slowing traffic, and it seemed more economical to pop back down to 5th for a quick boost back up to speed rather than leaving it in 6th and chugging back up that way.

 

[robin2660]

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 wouldn't say it "ruins" gas mileage. Yes, but it has to be hardly a blip on the screen. Fuel consumption at idle is miniscule and the ratio of time idling vs driving is small. I fell asleep once (drunk) and left my car running all night (9 hours). It used a half tank of gas.

I don't think warming his car is a significant factor in this reduction in fuel economy. Colder, denser air uses more fuel, winter gas has less energy per gallon, and possibly winter tires would account for most of the loss, and perhaps some snow to really rack up losses (short term). I also just read this web page about a Prius' gas mileage and temperature which shows, from 95F to 5F, a reduction in fuel economy from 53 to 38mpg. That's a big change. http://metrompg.com/posts/winter-mpg.htm

More reasons for poor fuel mileage in winter (from above):
9 reasons your winter fuel economy bites

1. More idling
2. Low tire pressure
3. Increased rolling resistance
4. Crappy road conditions
5. Lower average engine temperature
6. Higher average lubricant viscosity
7. Weaker gasoline
8. Higher electrical loads
9. More aerodynamic drag (A vehicle's aerodynamic drag is proportional to air density, and the density increases as temperature drops. For every 10 degree F drop in temperature, aerodynamic drag increases by 2% (source).

OP, where are you located?

 

[Igve2shtz]

otherwise you tell ME how i've never seen less that 20mpg EVER during my normal driving day. i must be doing something so wrong that beyond me, i make good gas mileage, and those who baby their rpms get 16mpg and are complaining about it? so i just shared how i shift and drive, to offer an alternative to pussyfooting based on a Prius's gas consumption rules.

I can not make assumptions as to why they are getting 16 mpg. All I know is that I shift at 3000-3500, hold about 10-5 inHg vacuum, and consistentally get 25 mpg city, and over 30 mpg highway.

And how do you know what the MPG is in your rental? Did you use your a Dashhawk because your dashhawk will need a new correlation factor to properly predict gas mileage. Also, if you use the old fashioned way of miles driven per gallon taken at the pump, how do you know the car was actually all the way full?

Anyway, thats all assumptions again. You mention you drive about 5-10miles uphill getting home from work, so that means you probably drive 5-10 miles downhill to get to work. If you coast in gear down hills, this will turn off the injectors increasing mpg.

But, nonetheless, now that you clearly defined your driving habit more than the previous post, I can understand if you are getting good mileage. I thought you were trying to state that you were going full boost all the time. Partial throttle boost will hold your AFR's in the 13's and 14's which is def a good compromise for hill climbing.

 

[Super Shredder]

yeah absolutely man, the downhill part isn't really coasting either, its pretty much one of the most serious roads around NJ, so throttle even downhill is needed because the awd needs to be in effect, so downhill i'm mostly in 4th at 3000rpm, and when it gets too steep and curvy, i downshift and accelerate through the turns, otherwise you get roll and loss of traction especially now with winter. uphill i am mostly in 4th around 2800 rpm where i can accelerate to get a nice astomspheric bypass and then slow myself down before too much of an extreme downshift is forced, its pretty much 100% active touge to and from my house. I'm just lucky my dog doesnt get carsick from it.

 

[robin2660]

<snip> so throttle even downhill is needed because the awd needs to be in effect, <snip>.

?????