Such bad mileage!!
 

Im reading 24 mpg average. I drive 80% of the time casually. Header exhaust tune. Yet i still only get about 240 miles per full tank. Wtf? I bought this car when j sold my jeep as i thought it would get way better mileage. These cars guzzle gas like a hummer

Flash back to stock

^

So it seems that you have a header-back exhaust along with a tune... well yes, you're going to get worse mileage. Better flow means your engine can breathe better... however breathing better also means breathing more. This means your engine will be using a bit more fuel, just the nature of the beast.

Add to that, your tune may eliminate the torque dip, but it serves a purpose and isn't just a random quirk with the car. The range where the torque dip is most commonly found is between 3k to 4.5k, highway cruising RPMs. Essentially, the torque dip helps with the car's MPG while cruising which ultimately helps with emissions. By flattening out the torque curve, you're sacrificing your MPG.

why complain about gas mileage when you bought a sports car that requires premium and you put on performance mods that will use more gas? you should have expected the mpg wouldn't be ideal or to your liking

if you can afford the car and the mods you shouldn't have to worry about gas i say

when I had my 370Z i was getting maybe 22mpg...i knew it came with the territory so i just ended up dealing with it

Idk what you have going on OP but I get 26mpg highway driving on e85. Over 30 on 93. I have stock headers but rest of the exhaust is catless and also have a tune.

How you drive is more important than what you drive. And I don't mean how you keep it <4k rpm or whatever.

Put an 86 on a flat windless highway at 55mph for a day and it will get >35 mpg.
Downhill you might hit 40 mpg.
Put an 86 in stop and go traffic for a day and it will get 19 mpg.
Flog an 86 on the track and it will get 10 mpg.

Put a Prius on a highway at 75mph for a day and it will get <40 mpg and not the 50+ plastered all over the advertising.

Here's my fill up log, averaging ~24-25 mpg with a city driving bias. Highs of ~35, lows of ~10.

http://www.fuelly.com/car/scion/fr-s...7974/fuelchart

Here's EPA ratings for the car, you have reported absolutely nothing abnormal.

https://www.fueleconomy.gov/feg/bymo...ion_FR-S.shtml

i have been shifting under 3k to save gas :D

Manual BRZ is rated at 22mpg city/30mpg highway/25mpg combined by the EPA, so 24mpg is right about where it's supposed to be.

I get 31mpg on my way to work trying to get good mileage, I get 25mpg on the way back enjoying myself on back roads. Just a catback...

Can't agree with this more. For my regular commute, give or take 80 miles depending on route, it's 90% freeway with about half an hour's worth of stop and go traffic. However, I love hyper-miling and can usually average between 34-38mpg. My car is mostly stock except for slightly taller tires (225/45 R17) which while being substantially grippier than the stock primacy's, also give it a little bit taller gearing.

By doing things like staying in gear instead of coasting, not trying to close every gap you see, and maintaining speeds when you can, you can drastically improve your gas mileage. But as other's have said, this wasn't a car designed for great mpgs... though it can definitely pull them off.

Granted, when the situation is appropriate, I'll flog this car like the rest. For normal driving though? What's the rush.

If you really want to improve your gas mileage, go back to a stock tune, but I think the extra 5 or 10 dollars at the pump is worth the smile factor (provided you're not driving like a wad).

Welp, @Norinradd ........ like said ...... you messed with the engine, now it's messing with your gas mileage.

For your reference, I get about 34 mpg highway, driving at or a bit above the speed limit, with the A/C on.


humfrz

Oh god. For some reason this thread comes as no surprise to me at all.


"like a Hummer" eh??


H1 Hummer
MPG: 9 city/12 highway


As per usual a bit of research could have went a long way before making asinine comments.


Out.

Just a catback here. Granted 80% of my M-F driving is just sitting in traffic, but every chance i get im usually romping through the gears and i rarley cruise under 4k. That plus about half a tank worth of hard canyon driving every weekend and i get anywhere between 23-25 mpg (per the read out).

I think thats pretty amazing tbh

Agree. When I'm having fun in my built motor, VF 6mt Forester, I get like 14mpg. On autocross days I usually get around 10mpg.

I love that the worst I've gotten, (being a fool on most of a tank, doing dyno pulls,) is 22mpg.

You might have a problem. How is your LTFT? If you have a very high -fuel trim, -15 to -25, you'll get terrible mileage but no CEL. A loose clamp on the throttle body intake connection or a vacuum line loose can cause that.

I'm averaging around 24 MPG but I do spend a lot of time in 10,000' mountain passes at 5500-6800+ RPM in 3rd gear. This was yesterday.

I've got OFH header, catback and stage2 tune, my mpg has barely dropped from what it was prior to catless header being installed. Haven't gotten less than 27 yet, usually it's high 28's or low 29s. probably 50/50ish city/hwy. Over 30 on actual long trips on the hwy. And this is with 91 California gas.

I average somewhere close to 30mpg combined city/highway. If I'm steady, I average 34mpg with big heavy tires and wheels.

I'd say you're driving it harder than you think, or your tune is not doing well.

you better patent that 24 MPG hummer and sell it, overnight billionaire

FYI I get like 20mpg mixed lol

Gas is cheap.


To sort your dilemma, I present this customised equation:


1 month's worth of your 'legitimate' extra dollars (or pennies) 'lost' due to 'poor' gas mileage

- a thousand and one other craptastic ways you blew Benjamin's that same month

+ your surprise that any mods would improve mileage and that you wouldn't be more tempted to hard press the go pedal after any upgrades
________________________________________

= trickle sideways steel plate in head economics



Cut out one daily coffee or bottled water, and floor that muthafucka.

I get about 180-200 miles before my gas light comes on...it's bad. Chicago driving, full exhaust/tune

I can't even fathom driving this car being worried about gas mileage all the time. I drive for maximum fun and whenever it needs gas, I fill up.

Hmmm im on E85 and i can almost get that economy in light traffic city driving, much better on highway, either your economy driving technigue is bad or ther is something wrong.
log the tune look at your cruising afr should be arround 14.7 and your ltft low less than 10%, if its over 10 you likely have and exhaust leak or a bad tune.

to get good economy you need to short shift keep rpm below 3000 and light throttle to keep enging load down

below is a typical fuel tables for open and closed loop you want to be in the less than 0.5 load areas at lower rpm for ecomomy.

https://i.gyazo.com/0fc20f1f7d34e6e3...ef918bdced.png

Yup, pretty much identical to what I've been getting.

highest ive ever had fro average mpg was 26.2 i believe couldve been 26.4 but thats when i had a stock exhaust and drove 3 hours away for vacation and drove back other than that i average 24.2 now that i have full exhaust catless and an intake i average 23.9

24's not bad all things considered.

LOL dude these cars aren't really great on gas for a four banger BUT its a helluva lot better than a jeep.

Old jeep 4l inline 6. 37" tires. One ton running gear id get 350 km to a tank. Tank was 55 litres. About 70$ to fill. Frs i get 350 km to tank and 50$ to fill up. .....same as jeep. Still costs me 20$ to go get groceries. And no. U buy a REAL sportscar to drive it and not worry about gas. 86 is a rwd economy car. Should get the same mileage as a ford focus or vw jetta. Im talking v8 or higher. 450hp or higher. This is a god damned 2cyl 4 banger in a super lightweight car. Should be amazing on gas. Not 350 km to a tank. I could also drive ALOT harder than i do. Raaaaarely do i get close to redline.

mileage is going to vary between states and geography. While someone might get 40, their highway speeds are 55-65, while others down south with speed limits of 75-85 and 100+degrees will get about 25-28mpg. Depends on region and if you really want to be a grandma holding up traffic

On 94 octane 15% ethanol, full headers and catback, LWCP, modified HKS V1 superchargsr and Ecutek dyno tune I am averaging approx 20 mpg/ 350 kms between fillups.

When cruising it is around 14.7 AFR, and as low as 12 AFR when accelerating.

Was getting several check engine lights, P0420 cat, P0068 powertrain and another one for bank 1 running rich.

Recently disconnected the leaky shit oil cooler and switched from 40 weight oil to 30 and now the check engine light seldom lights, and they go out on their own.

I guess thats the sacrifice going FI. I can chase the issues but sometimes its something that seems completely unrelated by the looks of things. Luckily I dont ever recall any knock, probably because it sometimes runs on the rich side.

Update: three days maybe 200 kmsincl.bumper to bumper commuting today, no CEL yet!

I sold my Jeep and bought this. 16mpg in Jeep 23/24mpg in the BRZ with just an OFT tune, (I do a lot of stop/go sitting in traffic). That's still about 50% better mileage than the jeep. I miss the Jeep, but have more fun driving in town with the twin. I never expected this to be an Economy car, I would have bought one of those if that was the priority.

That is some amazing math!

Some grade 4 math tells me that the jeep got 5 kilometers per $1 of gas but the FRS gets 7 kilometers.

In your world 5 =7?

That doesn't even take into account the difference in price between the regular gas for the jeep and the premium for the FRS. I would bet the mileage is 50% better or more.

Wait, wait, wait. Please point me in the direction of these gas sipping, 450hp, RWD Focuses and Jettas of which you speak.

Yah. 20$ difference from a twin to a burly old tj is pretty much no difference. Id expect to atleast double my fuel efficiency when moving from a big jeep to a tiny car

And i was saying. When someone buys a big powered american muscle car or big power european sportscar you can expect to get poor mileage. The twin is closer in relation to a ford focus than a corvette.

Well as i said. Mpg numbers aside. I paid 20$ dollars more for a tank in my jeep for the same amount of driving. That is NOT what the difference should be. The twin should double the efficiency of a big jeep

The average mpg for the same commute in three different cars I've owned:
2003 Nissan 350Z - 24mpg
2012 Golf R - 26 mpg
2016 Scion FR-S - 31 mpg

My commute is 26 miles one way, 21 miles of which is on I-25 with average speeds fluctuating between 80 and 90 mph depending on traffic. I'm actually impressed with FR-S and it's economy. I have no doubt I could average up to 34mpg if I parked it in the right lane and went 65-70 on the interstate. Maybe draft a hyper-miling Prius. But as it is, I don't think it's bad for a RWD car I can also flog at the race track or auto-x almost every weekend.

My e36 M3 got 18mpg on the exact same driving the FRS gets 28.

Both take premium fuel, so the FRS is considerably better.

AND more fun to drive!

Why should it .... ??

:popcorn:


humfrz

Have come to realize owners who get lower mpg numbers just drive the car as was intended. People who get 30+ mpg should sell the car as they arent driving it properly

:)