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Brand new 2013 WRX and MPG problem

18K views 45 replies 27 participants last post by  Rick James 
#1 ·
Hey guys, I'm a happy new owner of a 2013 hatch but I'm running into a problem. My first gas tank got around 20 mpg ( total miles divide by how many gallons I filled up). That's fine but I filled up last night and drove only 45 miles all day and the tank shows less than 3/4 tank now. I drove conservative (shifting btwn 2500-3000) and the dashboard says I'm averaging about 22.3 mpg. I don't know what I'm doing wrong. I'm taking the same route to work I did all week. Any ideas of what can be causing this?

Thanks,

Mo
 
#2 ·
is your drive all highway? or is it city type driving? is it hilly? how long is your commute (does the engine ever get up to temp)?

how do you accelerate? even if you shift at 2.5k-3k, if you go 1/2 throttle your guna lower your mpg.

Also, it's winter time so the winter grade gasoline is being sold, although it is cheaper (thankfully) it does reduce your fuel economy (i don't know to what extent).

I'm at 1000 miles now on my '13 hatch that i got 2 weeks ago and I've been averaging around 25.5mpg (miles drive/gallons filled up method) and any where from 25.8-26.4 (on the car average mpg).

I drive 90% highway at 65 mph usually (hit some traffic in certain spots), if i'm going for mpg i shift at or before 2.5k and accelerate smoothly (albeit, I guess it is rather slow sometimes). 5th gear at 45 mph and up seems to produce good fuel economy.

I'll do some 2nd-3rd gear pulls once in awhile, cause i didn't buy the car for fuel economy, but i still average about 25.5mpg
 
#3 ·
i have noticed that each notch on the fuel gauge equates to around ~35 miles that's just a rough estimate based on what i've observed. usually at half a tank i'm around 170-180 miles, but i've only filled up 4 times so far
 
#4 ·
My drive is approx 17 miles each way. half hwy and half on local streets. The street are level but doesn't matter because I take the same route everyday. I accelerate slowly not slamming on the gas at all. Because I had a full tank I was driving it conservatively to see how much mpg I would get but the opposite result happened. 45 miles traveled and more than 1/4 of my tank is gone. I have less than 300 miles on the car the only change that I have done was the tires. Conti DWS 235/45/17 same size as oem and those tires were on the car for majority of the first tank of gas. I am still riddled.
 
#5 ·
If what you are saying about each notch equaling 35 miles then I should still have more than 3/4 tank. Or at least 3/4's. I'm using 93 octane from a Hess station around the block. Maybe ill try Sunoco or BP gas. But can the name brand of gasoline be that different?
 
#33 ·
Maybe ill try Sunoco or BP gas. But can the name brand of gasoline be that different?
Don't know if brand matters, maybe try sunoco? Isn't that the brand nascar uses?
Brand makes no significant difference in mileage. For the most part, gas is all pretty much the same thing. At one point about 15-20 years ago Sunoco made a significant advance with their blending of detergents so they had a cleaner gas than anybody else on the market, but other companies have long since caught up.

I don't use cheap gas in the car - I use Sunoco or Exxon, 93 octane. I noticed, with my other cars, that cars drink cheap gas (delta, etc) like water.
Thinking "cheap" gas is any worse than name brand is totally false. Cheap gas is just name brand gas sold by a no-name station that doesn't pay the marketing fees associated with the use of the name brand. Their gas is refined and blended at the same refineries as name brand gas. What name brand they actually carry just depends on their distributor and can even change from day to day depending on what tanker delivers their fuel.

Here's a quick lesson on gas I've shared before. For the last 5 years I worked for the leading oil industry consulting company in the world and my customers included every single major and minor petroleum-related company and country in the world, so I know a small amount about this.....

Gas is mostly refined by refining companies and not retailers (only a couple of retailers have their own refineries). Anadarko is one of the largest companies in the world and the largest refiner in the world and 99.9999% of people have never heard of them, but I guarantee you've bought their gas. Retailers contract specific refining companies to create proprietary blends with specific additives in them. What exactly each retailer has the refiner put in their gas is a highly guarded trade secret. Most refiners companies produce gas for competing retailers, but with those different additives. Gas varies from batch to batch and also changes as it ages, so you never get exactly the same gas from the same retailer unless you buy it at the same exact day and time. Because of this, you can often buy name-brand gas that's worse than no-name gas because what you buy could be older or a poorer quality refinement than a no-name retailer happened to get.

No-name "cheap" gas is bought by the retailer from a distributor, but often they just get whatever blend the distributor happens to have in a tanker available for delivery in their area when the retailer wants it. This could be Mobil, Exxon, or any name-brand gas, but it's not poorer gas in any way. It would cost a refiner more to produce a "cheap" version of gas than to just produce more than a particular retailer wants. The refiner also doesn't just produce the exact amount ordered but produces a particular quantity based on a number of things including how long they happen to have a cracker, blender, or other equipment available for at that time.

So to put it simply, forget about non-name brand retailers selling "cheap" or inferior quality gas because it simply doesn't exist.

Your car is fine. The gas gauge isn't 100% linear, so while it might appear to sink quickly at the beginning, it will steady out. My bugeye will drop 1/8th or more in the first 50 miles, then the needle seems to drop more slowly. Now if you suddenly see the needle drop to empty, and you find after dividing the trip meter by the gallons purchased that you're getting 12 mpg or something, then that is a legitimate cause for concern.

It sounds like you just need to get more familiar with the car, honestly. I think you'll be fine. :)
+1 using the distance your needle moves to calculate mileage is completely useless. You need to use the odometer and how many miles you get between filling up your tank and how many gallons the pump tells you you put in.

All the moving parts inside an engine will have rough edges when the engine is new. It'll be wearing in for about the first thousand miles. I'd forget even looking at mpg until you get there.
Definitely true. Gas mileage is usually significantly lower for the first 1000 miles or so.
 
#6 ·
I've had my wrx for 3400 miles now. I've never reset my second trip odometer and it says I've gotten 19.8 mpg so far for the life of the car. I do drive spirited I live in the back roads and probably do about 30% of my driving on the highway so of course I am a little low on mpg. But I wouldn't expect great mpg, hope this helps
 
#7 · (Edited)
I use BP 93 octane, mostly because it's right by where i work and the fact that it's 15+ cents cheaper than anywhere else i've seen doesn't hurt. Don't know if brand matters, maybe try sunoco? Isn't that the brand nascar uses?

And as far as the whole notch thing = 35, that was a REAL rough estimate and based on however I was driving at the time. It's more realistically around 30 or so
 
#8 ·
I doubt this is your issue, but I noticed it definitely had me scratching my head.. I park on a sloped driveway and knew I didn't have a full tank of gas but because of the slope, it read a full tank for a good 15 miles before it started dropping (and fast) to its accurate level. My former WRX and other cars never took that long to register accurate or even get effected by the slope so maybe thats a possibility? just throwing out ideas.
 
#9 ·
Thanks for the replies guys, the only explanation is that the gas stopped pumping before it was full and didn't notice if the guage actually went to Full. I only noticed the issue when I came home from work. From about 1/4 tank left I filled up 11.7 gallons. What is the capacity of our tanks not including emergency tank?
 
#11 ·
Rex, how many miles do you have on your car? Until you get used to driving the car the mpg's will vary. Having a heavy right foot doesn't help as well. Also remember that everyone is on winter gas. I'm tuned but I get around 75miles per quarter of the gas gauge.

There are plenty of plenty of threads on this site about mpg's. I suggest reading through those and checking it out. If all else fails goto your local stealership.
 
#14 ·
Rex, how many miles do you have on your car? Until you get used to driving the car the mpg's will vary. Having a heavy right foot doesn't help as well. Also remember that everyone is on winter gas. I'm tuned but I get around 75miles per quarter of the gas gauge.

There are plenty of plenty of threads on this site about mpg's. I suggest reading through those and checking it out. If all else fails goto your local stealership.
 
#16 ·
Your car is fine. The gas gauge isn't 100% linear, so while it might appear to sink quickly at the beginning, it will steady out. My bugeye will drop 1/8th or more in the first 50 miles, then the needle seems to drop more slowly. Now if you suddenly see the needle drop to empty, and you find after dividing the trip meter by the gallons purchased that you're getting 12 mpg or something, then that is a legitimate cause for concern.

It sounds like you just need to get more familiar with the car, honestly. I think you'll be fine. :)
 
#21 ·
The gas gauge isn't 100% linear, so while it might appear to sink quickly at the beginning, it will steady out. My bugeye will drop 1/8th or more in the first 50 miles, then the needle seems to drop more slowly.
Really? My Bugeye will sit at completely full for the first 50-60 miles then drops quickly to 3/4 evening out consistently to the gas light. Weird.

Also to the OP the computer my not be 100% accurate. My mom's A6 is usually 1-2 mpgs off from the calculated mileage and my dad's F-250 Superduty is about the same almost always below the calculated mileage.
 
#17 ·
All the moving parts inside an engine will have rough edges when the engine is new. It'll be wearing in for about the first thousand miles. I'd forget even looking at mpg until you get there.

However, Subaru's website states 19mpg city and 25 highway (freeway?). So if your commute is made up of different types of roads, 22mpg would be a fair combined mpg figure. I've got nearly 7000 miles on my '12 WRX. I reset the trip counter (and consequently, the average mpg counter) every time I fill up, and at the end of each tank of gas I've never seen anything but 23-24mpg average. I'd say 20mpg with your first tank is nothing unusual.
 
#18 ·
I would have to agree with people saying that winterblends tend to have an effect on your MPG's but I also like to think that your normal break in period will effect your MPGs as well... at least on my GTR I didn't see 22mpgs until i had about 10k on the motor.

I do believe that most new owners think they are shifting around 3500rpms but lets be realistic maybe you are shifting a tad higher then you believe. Its a new car with some decent power the car can be exciting. My fiancee 12' is getting around 24.5mpg right now but she always drives like a granny. And I do believe with time it will get a little better.
 
#22 ·
I don't use cheap gas in the car - I use Sunoco or Exxon, 93 octane. I noticed, with my other cars, that cars drink cheap gas (delta, etc) like water.

I have noticed (and it's odd) but if I drive on the highway around 60 in 4th gear, with the car 'working' a tad, it gets better gas mileage! It seems to 'like' that power band. Nonetheless, it's not a 'gas mileage' car, although considering it's a 'torque car', it gets pretty good mileage.
 
#23 ·
My car has about 500+ miles on it now. And I think you guys are right about a couple things. The gas guage definitely isn't accurate and I probably have a heavier foot than I realize. I drove my other car that the wrx replaced and realized how much slower it was daily driving. I also realized that driving the car at 2k sometimes decreases gas mileage. The slight inclines that a person may not notice probably puts more strain on the engine causing mpg to drop. I drove my car like I did the first week and got better gas mileage than trying to be very conservative.
 
#24 ·
If you're getting over 20 mpg you are doing well compared to me. I'm lucky to crack 18 in the city. I've only seen 23 on the freeway once and that was staying below 75 mph. AWD, turbo + heavy foot do not = good mileage, but I expected that when I bought mine. I was a bit surprised that my Eclipse got better mileage though.
 
#25 ·
Yes its a Performance car so not really too worried about low 20s but, I have 5k on my 2013 now

I just got 23.6 mpg(24.7 indicated) on 7.65 Gallons by driving 60-65 on the highway to and from work. With 2 miles of city each way round trip of 77 miles, so roughly ~4 gallons per day I use.

I hear some people getting 25-28 driving this speed but I never confirmed it. I have to drive 55-60 for Indicated 27mpg

Sounds normal or low?
 
#26 · (Edited)
Yes its a Performance car so not really too worried about low 20s but, I have 5k on my 2013 now

I just got 23.6 mpg(24.7 indicated) on 7.65 Gallons by driving 60-65 on the highway to and from work. With 2 miles of city each way round trip of 77 miles, so roughly ~4 gallons per day I use.

I hear some people getting 25-28 driving this speed but I never confirmed it. I have to drive 55-60 for Indicated 27mpg

Sounds normal or low?[/QUOTE

If you are seeing 27mpg then that is awesome. I have a 2013 with 3100 Miles on ODO and l average 22 to 24mpg in a daily mixed commute of 30 Miles with speeds varying between 45-75mph:)
 
#28 ·
I'm only concerned because I only drove back and forth to work and lost over a 1/4 tank. I obviously know that it wasn't a Prius but to get the same gas mileage as a hummer is ridiculous. Wanted to verify if this was normal during the break in period or if possibly the guage or sensor could be defective.
 
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