MPG Thread

[covertrussian]

There are a bunch of these threads, we should have one be stickied. Here are my numbers:

 

2005 LGT 5MT (Downpipe, turbo inlet, side gaped spark plugs)

100% city Calm driving - 17mpg, this is with 25mph average, 8miles a day

100% city aggressive driving - ~14-16mpg

70mph Highway - 30mpg personal best, 28mpg average.

 

So, I drove 73.4 miles and it took 2.472 gallons. Thats an average of 29.69MPG, about 95% highway. My in car gauge said something like 28.2

 

Not to diss your numbers, but I've noticed that doing short trips (under 100miles) yields inaccurate results on all of my cars. On my LGT I've gotten 31.5mpg filling up at 80miles (when it would get ~27mpg on 100+mile trips). On my other car I would get 38mpg filling up around 70miles, while usually it would be 30mpg.

 

On my 2005 Outback XT I've found the computer to be within +/- 1MPG of the hand calculated value. Hand calculated isn't very reliable itself...one assumes the fuel added is the fuel consumed. However that's not a good assumption.

 

If you fill up similarly you will receive fairly consistent hand calculated numbers. For one I always fill up on the slowest speed the pump has, and I always let it punch out twice.

 

My gauge compared to real MPG is off by 10% on average, but I've had it be off by 17% too. Keep in mind that even though it's off by only 1mpg, when your in single digits 1mpg = 10%.

 

I've found the hand calculation and computer come into alignment as more time and mileage pass. This allows the highs and lows to average out. It seems reasonable to me that, given steady state driving, 29.4 MPG is achievable on the highway.

 

I don't know about you guys, but I for the life of my car could not get above 25mpg. The only time I started getting more then 25mpg is after I started ECU tuning.

[08 LGT]

20 MPG mixed, if more city driving than highway

21 MPG mixed, if more highway than city

 

19 MPG city only

25 MPG highway only (cruising between 75-85 MPH)

[08 LGT]

 

I don't know about you guys, but I for the life of my car could not get above 25mpg. The only time I started getting more then 25mpg is after I started ECU tuning.

 

 

Sounds about right from what I've read from people who have had their car tuned. The only way I can ever get 28 MPG is on a 55 MPH country highway with cruise control on around 60 MPH. I need to do a stage 1 tune...

[08 LGT]

Hand calculated? Sounds like you're trusting the generally optimistic HUD.

 

Whenever I've compared a manual calculation to the estimated MPG, my car is pretty much dead on the money.

[sunny5280]

Seems achievable to me as well, but not if the HUD says that's what it's getting. You aren't the first person to tell me you're display is reasonably accurate, but you're part of such a small minority that the exceptions barely dent the rule. Particularly once you leave stock, but that's another thing entirely.

The problem is we can't say for certain if the computer is off or not as we have no reliable way to compare it.

 

As for how reliable hand calculating is, it's completely dependent upon consistency at the fill up. Lots of things come into alignment over time, but depend on them in your practical tank to tank application at your peril.

It's completely dependent on the assumption the amount of fuel added on fill up is the same consumed prior to fill up. That's an assumption I'm unwilling to support. It is for this reason why averaging is a more reasonable way to determine mileage. I've learned calculating mileage from tank fill to tank fill, be it computer or hand, is almost meaningless.

[Max Capacity]

Hey has anybody else noticed the car get better mpg when you switch brands of gas ?

 

I normally run Gulf 93, the other week I filled up with Sunoco 93. It seemed to get a little better mpg for that tank.

 

I have noticed this over the years with both cars.

[sunny5280]

I don't know about you guys, but I for the life of my car could not get above 25mpg. The only time I started getting more then 25mpg is after I started ECU tuning.

That's odd as I easily achieve 28 MPG on the highway.

[sigmafour]

I notice I have less than stellar performance with anything other than Shell or Sunoco.

[08Legacy-GT]

I notice I have less than stellar performance with anything other than Shell or Sunoco.

I only put in shell 93

[08Legacy-GT]

Hey has anybody else noticed the car get better mpg when you switch brands of gas ?

 

I normally run Gulf 93, the other week I filled up with Sunoco 93. It seemed to get a little better mpg for that tank.

 

I have noticed this over the years with both cars.

V powahh

[08Legacy-GT]

20 MPG mixed, if more city driving than highway

21 MPG mixed, if more highway than city

 

19 MPG city only

25 MPG highway only (cruising between 75-85 MPH)

Right on with me.. Less mixed more city since I have a heavy foot

[covertrussian]

Sounds about right from what I've read from people who have had their car tuned. The only way I can ever get 28 MPG is on a 55 MPH country highway with cruise control on around 60 MPH. I need to do a stage 1 tune...

 

I got 25mpg tops at 70mph. If your getting 25mpg at 75-85mph try slowing down and you should be in 27+ range.

 

Hey has anybody else noticed the car get better mpg when you switch brands of gas ?

 

I normally run Gulf 93, the other week I filled up with Sunoco 93. It seemed to get a little better mpg for that tank.

 

I have noticed this over the years with both cars.

 

They might use less ethanol. I religiously use Shell 93. I am planning on using Pure/Royal 93 ethanol free gas soon to test the difference.

 

That's odd as I easily achieve 28 MPG on the highway.

 

Not here, at least not in the winter months. Every car is going to be different, I live in the mountains so I loose a good amount of mpg going up and down the hills (even on highway).

 

I started getting 26+mpg after I set my AVCS to be 10-15* at 70mph.

[Rhitter]

24 mpg hwy for me. Generally can't get better than that. If I drove at 60 mph it might improve but 70-85 is 22-24 mpg hwy.

 

City can go as low as 16 mpg.

 

I use shell / chevron 91.

[Terbow]

I can't say for sure whether or not my car has a tune, as far I know its stock.

 

Everyone running synthetics, trans, diffs, engine? Recent tune up (not tune), air filters, plugs etc? Correct tire pressure? Miles? Worn bushings, suspension components, etc? Car loaded down with crap, kids, work related items? Those are just a few factors that can effect your MPG. I shouldn't even have to mention driving habits, but apparently some of you need direction. I like how a few of you are quick to point out what someone should/shouldn't be/can't or aren't getting.

[MrTris]

I can't say for sure whether or not my car has a tune, as far I know its stock.

 

Everyone running synthetics, trans, diffs, engine? Recent tune up (not tune), air filters, plugs etc? Correct tire pressure? Miles? Worn bushings, suspension components, etc? Car loaded down with crap, kids, work related items? Those are just a few factors that can effect your MPG. I shouldn't even have to mention driving habits, but apparently some of you need direction. I like how a few of you are quick to point out what someone should/shouldn't be/can't or aren't getting.

 

We've been at this longer than you have, but, feel free to pave your own YBR, there, Munchkin.

[Rhitter]

I can't say for sure whether or not my car has a tune, as far I know its stock.

 

Everyone running synthetics, trans, diffs, engine? Recent tune up (not tune), air filters, plugs etc? Correct tire pressure? Miles? Worn bushings, suspension components, etc? Car loaded down with crap, kids, work related items? Those are just a few factors that can effect your MPG. I shouldn't even have to mention driving habits, but apparently some of you need direction. I like how a few of you are quick to point out what someone should/shouldn't be/can't or aren't getting.

 

My driving habits are terrible and my car is frequently loaded with 500 pounds, everything else suspension wise is newish. I over inflated my tires which I think gave me 1 mpg more and madecornering feel a lot better (stupid squishy DWS). Any chance to go WOT I take.

[BoozeRS05]

20 MPG mixed, if more city driving than highway

21 MPG mixed, if more highway than city

 

19 MPG city only

25 MPG highway only (cruising between 75-85 MPH)

 

Right on with me.. Less mixed more city since I have a heavy foot

 

About spot on for me too..

 

I calc my mpg every tank, and my carputer is pretty close, usually +0.5-1mpg. Cobb stg2, Sunoco 93, but prefer Shell Vpower just isn't available.

[Terbow]

We've been at this longer than you have, but, feel free to pave your own YBR, there, Munchkin.

 

[Terbow]

Mr. T, in no way was I tryin to explain why people's MPG are what they are. If you read the entire thread, you'd see those that have the mentality of the know it all. Above that, I was being facetious. Hard to tell via text some times.

[Mike07LGT]

Stage 2 here, best I can get is 26mpg highway, and I average around 22/23 under normal driving conditions. I rarely drive spirited or out of control haha

[shortfusemonkey]

im all stock for the time being, city I average 18ish and highway is about 23/24 but I do have a heavy foot 133k as well. I do want to start using Shell gas, there is only one station near me that sells it though....

[sunny5280]

Not here, at least not in the winter months. Every car is going to be different, I live in the mountains so I loose a good amount of mpg going up and down the hills (even on highway).

I do agree each vehicle is going to be different based on driving conditions, location, etc. But the variation seems quite high to me.

 

As for driving in the mountains the highway mileage I provided is partly on mountain driving. My family lives in the mountains so about half of the drive is through the mountains. I suspect if I were driving a flat road in Texas I might get even better http://legacygt.com/forums/images/icons/icon14.gif

[Max Capacity]

I can't say for sure whether or not my car has a tune, as far I know its stock.

 

Everyone running synthetics, trans, diffs, engine? Recent tune up (not tune), air filters, plugs etc? Correct tire pressure? Miles? Worn bushings, suspension components, etc? Car loaded down with crap, kids, work related items? Those are just a few factors that can effect your MPG. I shouldn't even have to mention driving habits, but apparently some of you need direction. I like how a few of you are quick to point out what someone should/shouldn't be/can't or aren't getting.

 

 

Notice my post count, like MrTris said, some of us are not new to this game.

 

I bought my 05 GT wagon new, late June 04. it's always gotten 22-25mpg for a overall average, It's been off the stock MAP since 8000 miles on it when Cobb AP V1 came out Dec 04. I alway's noticed it gets better mpg driving home from VT after our weekends skiing. Must be all down hill to CT.

 

The car spent its first 154,000 miles on dino oil. The past few years I find myself driving a bit slower in the highway to keep the turbo out of boost. I think that's the key to good mpg.

 

My 98 and 00 GT wagons (both 5mt's) would get the same mpg on the same drive back from VT, then averaged out over the week. Friends with the same years, outbacks get the same 22-25mpg over all average. The newer outbacks owners are getting better mpg.

[08Legacy-GT]

Notice my post count, like MrTris said, some of us are not new to this game.

 

I bought my 05 GT wagon new, late June 04. it's always gotten 22-25mpg for a overall average, It's been off the stock MAP since 8000 miles on it when Cobb AP V1 came out Dec 04. I alway's noticed it gets better mpg driving home from VT after our weekends skiing. Must be all down hill to CT.

 

The car spent its first 154,000 miles on dino oil. The past few years I find myself driving a bit slower in the highway to keep the turbo out of boost. I think that's the key to good mpg.

 

My 98 and 00 GT wagons (both 5mt's) would get the same mpg on the same drive back from VT, then averaged out over the week. Friends with the same years, outbacks get the same 22-25mpg over all average. The newer outbacks owners are getting better mpg.

 

While 15k is impressive, if it's filled with comments like "We've been at this longer than you have, but, feel free to pave your own YBR, there, Munchkin." then I'd say they arent all constructive.

[covertrussian]

I'm surprised some of you even get 25mpg going at speeds that you go at. I live in VA where going above 75mph is a sin. This is why I still do all of my MPG testing at 70mph. I haven't tested out enough variables to test the 75mph MPG.

 

No need for anyone to be condescending, I just noticed that people don't include enough data or consistency in their numbers. This is why my MPG numbers are generally way lower then the rest. If I'm doing City MPG test, I try to avoid even 45mph back roads.