Gas Mileage

[Al]

Yea one more thread out of millions. Just so amazing yow much better gas mileage you can get using a light pedal and not having so sit in traffic (duh)
Comparing my '19 Crosstrek 2.0 to my '18 Froester 2.0. ..Starting with engine cold on a 70 degree day on a 4 mile course I can get 40mph on the Trek and 30 on the XT. Obviously this is very very careful driving. Country road and 2 stops. If there were a vehicle in back of my he would be [censored] but I did the 35 to 45 mph speed limit.

Just driving normally will yield 21 on the XT and 28 on the Trek. So we are looking at 30% savings on the XT 30% saving on the Trek (no I did not fudge the numbers. I considered changing one to make it look better..lol) with very very careful driving. Its certainly reasonable that one could get close to 20% savings with just prudent driving.

Obviously under many conditions this option is not possible. And note that the "very very careful" driving situation involved taking the engine temperature from 70 to about 175F.

Nationally it would appear that the U.S. could save 10% of the 385 million gallons per day or 35 million gallons or 100 million dollars. Probably close to a buck a day per "average" driver

Thanks on this board to all who serve(d)

 

[ARCOgraphite]

Turbos are tuned rich and don't make much torque off boost. My wife gets over 33 ave on her Crosstrek. Good trans and engine tuning. The Fuji CVT locks up the little torque converter IMMEDIATELY when under way (
My new lease VW gets low 40's around town with careful driving - but not so sluggish as to PO the person behind you.

Not bad for a turbo. And better than anything we've owned. The only thing that came close was a mid 80's dodge colt 4 speed manual with a stratified lean burn engine. That avereaged around 37mpg.
Back to the VW - Under boost the instant MPG is Around 7mpg. so you have to stay out of it. The big downside is the engine is very agricultural, coarse and boring when back pedaling it. Too bad the car handles like a 62 mercury comet. It does stick once it keels over though - Which the' Comet didn't

 

[fdcg27]

I've observed this personally.
A 10% fuel economy gain is easily achieved with careful and attentive driving.
How many people zoom around you on the way to a red light and then brake hard to stop?
Then they wonder why they need brakes and tires so often as well as why the fuel economy they see sucks.

 

[SubieRubyRoo]

Al, I'm currently working on the exact same thing with my 2 Subies, which are even closer brethren than yours: 05 Outback and 07 Impreza, both with EJ253s and 4EATs. My Impreza is currently getting about 32.9mpg with me driving it to work and back (23 miles each way, 7 stop signs, no lights) and my wife is getting around 22.9mpg in the Outback (much shorter trips, heavier foot, nearly all in-town driving). However, when I drive the Outback on my work route, I usually put down about 28.2mpg, and when I bring up this 5+ mpg discrepancy between our driving habits, I am met with an eye roll.

One thing I don't understand though; for a car that is only a couple hundred pounds heavier, the Outback is programmed to shift at much higher RPMs per throttle opening than the Impreza. Under feather throttle, both will shift into OD right around 28-30 mph, but under say 1/4 - 3/8 throttle the Impreza will shift around 3400 rpm and the Outback will shift around 4400 rpm (matching butt dyno acceleration rates). I know there is a very slight discrepancy in HP & torque due to the camshaft phasers on the 07, but it seems the Outback revs excessively and definitely holds the lower gear way too long when using resume on the cruise control. I've even done a hard clear of transmission learning using FreeSSM on both cars and still get the same results. The way I drive the Impreza nets a roughly 50% mileage increase over what the wife gets in the Outback!!

 

[CT8]

Have you ever heard of the CAFE standards?

 

[MCompact]

I have a 12 mile commute; traffic is usually light but I rarely see north of 65 mph. Most days I take the Clubman and I've seen as high as 40+ mpg for the round trip. In contrast, the 2er might hit the low 30s.
The only real downside to the Clubman is that I have to park it next to my assistant's Cayman S...

 

[bullwinkle]

I can consistently get 25 MPG in the MGM in my sig-IF I can get out on the back roads & maintain 55-60 MPH with a light foot. Which would get me KILLED on the local interstates!

 

[Ws6]

Originally Posted by Al
Yea one more thread out of millions. Just so amazing yow much better gas mileage you can get using a light pedal and not having so sit in traffic (duh)
Comparing my '19 Crosstrek 2.0 to my '18 Froester 2.0. ..Starting with engine cold on a 70 degree day on a 4 mile course I can get 40mph on the Trek and 30 on the XT. Obviously this is very very careful driving. Country road and 2 stops. If there were a vehicle in back of my he would be [censored] but I did the 35 to 45 mph speed limit.

Just driving normally will yield 21 on the XT and 28 on the Trek. So we are looking at 30% savings on the XT 30% saving on the Trek (no I did not fudge the numbers. I considered changing one to make it look better..lol) with very very careful driving. Its certainly reasonable that one could get close to 20% savings with just prudent driving.

Obviously under many conditions this option is not possible. And note that the "very very careful" driving situation involved taking the engine temperature from 70 to about 175F.

Nationally it would appear that the U.S. could save 10% of the 385 million gallons per day or 35 million gallons or 100 million dollars. Probably close to a buck a day per "average" driver

Thanks on this board to all who serve(d)

Wow. I really expected better from the Forester than 21mpg being driven normally.

 

[RDY4WAR]

On previous trips out of town, I've typically just set the cruise control in the Tahoe at 75 mph, and let it do the work. The best it ever got like that, in cool weather, no AC or heat going, and just me in it was 19.12 mpg. This trip I'm on now, I've been keeping it closer to 65 mph, coasting as much as possible, letting it drop off 5 mph or so going uphill, saving acceleration for downhill, and using as little gas or brake pedal as necessary. Loaded down with 5 people, luggage, food/drinks, AC going the entire way, and it managed 21.87 mpg. That's over a 14% improvement and saved me over $30 on the round trip.

 

[eljefino]

My prius is set up for slower= better. I've pulled some amazing MPG stuck behind a school bus.

 

[Quattro Pete]

Originally Posted by Al
Just driving normally will yield 21 on the XT and 28 on the Trek. So we are looking at 30% savings on the XT 30% saving on the Trek

Be careful when using MPG figures to calculate savings %. It is misleading because we in the US insist on measuring miles per gallon instead of gallons per mile. This is why the newer EPA window stickers also show fuel consumption in gallons per 100 miles, alas, we are too accustomed to MPG to even look at them.

In reality, a jump from 21 MPG to 28 MPG is only about 25% savings, not 33% that the MPG math would have you believe.

It might help to look at it from a a distance perspective. Let's take 100 miles:

If you average 21 MPG, you'll need 4.76 gallons of fuel to go 100 miles.
If you average 28 MPG, you'll need 3.57 gallons of fuel to go 100 miles.

When you do the math, that's a 25% reduction in fuel needed, or 25% savings.


https://www.fueleconomy.gov/feg/label/learn-more-gasoline-label.shtml

https://www.popularmechanics.com/cars/a12367/4324986/

 

[LotI]

Thanks for pointing this out Pete. I've been preaching g/100mi for years(or l/100k). Makes more sense when comparing vehicles.

I've also been talking about SAE grades, not weights. But that's uphill too!

 

[Al]

Originally Posted by SubieRubyRoo
Al, I'm currently working on the exact same thing with my 2 Subies, which are even closer brethren than yours: 05 Outback and 07 Impreza, both with EJ253s and 4EATs. My Impreza is currently getting about 32.9mpg with me driving it to work and back (23 miles each way, 7 stop signs, no lights) and my wife is getting around 22.9mpg in the Outback (much shorter trips, heavier foot, nearly all in-town driving). However, when I drive the Outback on my work route, I usually put down about 28.2mpg, and when I bring up this 5+ mpg discrepancy between our driving habits, I am met with an eye roll.

One thing I don't understand though; for a car that is only a couple hundred pounds heavier, the Outback is programmed to shift at much higher RPMs per throttle opening than the Impreza. Under feather throttle, both will shift into OD right around 28-30 mph, but under say 1/4 - 3/8 throttle the Impreza will shift around 3400 rpm and the Outback will shift around 4400 rpm (matching butt dyno acceleration rates). I know there is a very slight discrepancy in HP & torque due to the camshaft phasers on the 07, but it seems the Outback revs excessively and definitely holds the lower gear way too long when using resume on the cruise control. I've even done a hard clear of transmission learning using FreeSSM on both cars and still get the same results. The way I drive the Impreza nets a roughly 50% mileage increase over what the wife gets in the Outback!!

Sorry. I must have had too much CBD on my neck when I posted.
The XT gets 24+ and it looks like with similar driving the XV will get 31 in every day driving.

BTW I can relate to what you were saying about the wife. I get at least 10% better gas mileage than her..mainly bc she doesn't coast at all when stopping. Uses breaks at the last few seconds. Yes I tried to change her.

And the mileage you are getting with the EJ engine is fabulous. my 08 Forester got almost exactly the same as the XT gets now. On a trip it was difficult to impossible to get 31 mpg.

Took a 130 mile trip this morning with the XV, after allowing for 3 mpg consumption readout it was 36.9 mpg. Not this is with very conservative driving.The XT might get 29

 

[bullwinkle]

Originally Posted by eljefino
My prius is set up for slower= better. I've pulled some amazing MPG stuck behind a school bus.

That's where the big MPG is-slowest speed it will hold OD & keep the converter locked, drafting off a bigger vehicle. I remember C&D winning the MPG competition when the Insight first came out by modding the back of an Excursion & following very, VERY closely!

 

[Cujet]

The time saved by going fast is, quite simply, amazingly cheap.

Like many, I'm nearly obsessed by fuel economy. I've even modded cars for significantly better MPG.

However, time is the whole of your capital. Anything that gives me extra free time has great value.

So, I'm much more interested in going fast economically. I have no interest in spending an hour to save $3

 

[SevenBizzos]

Originally Posted by Cujet
The time saved by going fast is, quite simply, amazingly cheap.

Like many, I'm nearly obsessed by fuel economy. I've even modded cars for significantly better MPG.

However, time is the whole of your capital. Anything that gives me extra free time has great value.

So, I'm much more interested in going fast economically. I have no interest in spending an hour to save $3


Yes, time is a very valuable commodity. Spending an additional hour in my car in an effort to save a gallon of gas in increased MPG isn't a great use of my time. My work commute includes a four lane highway (four lanes the same direction). I could go the posted speed limit in the right lane and be a danger to the road, or go 82 mph, lower my MPG by 5-6, and get to work/home sooner.

My fuel efficiency is wasted on a) series of stop lights not in sync, b) E10/winter blend, and c) stop lights at intersections that have 20 cars an hour use them for access to a highway (aka unnecessary). My fleet of vehicles is my choice and obviously fuel efficiency isn't part of my consideration when buying.

But I respect you guys that want to squeeze more out. From vehicle choice, to driving style, to trip efficiency. I get it. But please stay in the right lane and try to accelerate a little when entering a higher speed roadway. Your real time MPG calculator will return to glory once you're up to speed.

 

[Al]

Originally Posted by Cujet


So, I'm much more interested in going fast economically. I have no interest in spending an hour to save $3

Yea..I get it. But I like listening to oldie xm tunes and quite simply relaxing when I drive.

To me going fast is a statistical non starter and I am not even thinking of money..thats not even on my radar.. Mostly its about conserving resources. BUT..... Driving 70 mph for one hour a distance of 60 miles will save you 8 1/2 minutes. If you are involved in an accident 22% more energy will be released (at 70) than at 50 resulting in that much more injury/damage.

"This shows that a 1% increase in average speed results in
approximately a 2% increase in injury crash frequency, a 3% increase in severe crash frequency, and a
4% increase in fatal crash frequency"

So there will be a 33% increase of an injury crash , 50% increase in a severe injury crash and a 66% increase in a fatality frequency.
So in the best case you will have 1/3 more "crash" risk going 70 instead of 60.

I know..on the internets we individually are the best drivers of anyone

I am a statistical person. I don't fret about bad stuff..but I always minimize gross risk. I waited 13.7 billion years to be born, I'm not leaving this world bc I failed to use what intelligence I have..

 

[MCompact]

My commute is so short that I don't notice much difference between pushing it and just cruising. That said, if no one is in front of me I drive at least 5 mph over the speed limit so as not to hold up other traffic.

 

[hpb]

Originally Posted by Quattro Pete
Originally Posted by Al
Just driving normally will yield 21 on the XT and 28 on the Trek. So we are looking at 30% savings on the XT 30% saving on the Trek

Be careful when using MPG figures to calculate savings %. It is misleading because we in the US insist on measuring miles per gallon instead of gallons per mile. This is why the newer EPA window stickers also show fuel consumption in gallons per 100 miles, alas, we are too accustomed to MPG to even look at them.

In reality, a jump from 21 MPG to 28 MPG is only about 25% savings, not 33% that the MPG math would have you believe.

It might help to look at it from a a distance perspective. Let's take 100 miles:

If you average 21 MPG, you'll need 4.76 gallons of fuel to go 100 miles.
If you average 28 MPG, you'll need 3.57 gallons of fuel to go 100 miles.

When you do the math, that's a 25% reduction in fuel needed, or 25% savings.


https://www.fueleconomy.gov/feg/label/learn-more-gasoline-label.shtml

https://www.popularmechanics.com/cars/a12367/4324986/



Great post, absolutely correct! Most of the world has been measuring fuel economy in litres per 100 kilometres for at least the last 20 years.

 

[fdcg27]

Originally Posted by Quattro Pete
Originally Posted by Al
Just driving normally will yield 21 on the XT and 28 on the Trek. So we are looking at 30% savings on the XT 30% saving on the Trek

Be careful when using MPG figures to calculate savings %. It is misleading because we in the US insist on measuring miles per gallon instead of gallons per mile. This is why the newer EPA window stickers also show fuel consumption in gallons per 100 miles, alas, we are too accustomed to MPG to even look at them.

In reality, a jump from 21 MPG to 28 MPG is only about 25% savings, not 33% that the MPG math would have you believe.

It might help to look at it from a a distance perspective. Let's take 100 miles:

If you average 21 MPG, you'll need 4.76 gallons of fuel to go 100 miles.
If you average 28 MPG, you'll need 3.57 gallons of fuel to go 100 miles.

When you do the math, that's a 25% reduction in fuel needed, or 25% savings.

https://www.fueleconomy.gov/feg/label/learn-more-gasoline-label.shtml

https://www.popularmechanics.com/cars/a12367/4324986/



I think that most people who actually care are already aware of this, but the point is that the more efficient vehicle always saves its driver fuel and money.