Everyday Driver "Greatest Hits" - Eco Mustang v. WRX v. FR-S v. FiST

[JS + BRZ]

Not trying to side with anyone...

But my previous car was a Mazdaspeed3, it was modded and as fast as the stock STi and EVO on the freeway.

I was getting a better gas mileage on that car over my BRZ. That's how turbocharged cars work.. if you are not on the boost range, you could get a great mileage out of it. And just for daily driving, you don't have to be on boost. Just my 2 cents.

[abraxis]

Originally Posted by JS + BRZ

Not trying to side with anyone...

But my previous car was a Mazdaspeed3, it was modded and as fast as the stock STi and EVO on the freeway.

I was getting a better gas mileage on that car over my BRZ. That's how turbocharged cars work.. if you are not on the boost range, you could get a great mileage out of it. And just for daily driving, you don't have to be on boost. Just my 2 cents.

Yeah, my stock Legacy GT gets around 23mpg combined. Maybe it doesn't know how turbos work? Maybe Toyota doesn't either which is why there aren't any on the Prius or other hybrids?

What is the EPA/DOT doing wrong that their certified numbers don't bear this out? Granted they do a lot wrong in general, but let's keep on topic heh.

IME driving a turbo car completely out of boost is akin to trying to stay in electric mode on a Prius. Horrible experience for DD. Maybe our ideas of "out of boost" are different.

Well, let's stay focused on the '15 WRX rather than introduce another variable with no comparison like a modded Mazda 3 that's > an Evo.

I'm just looking for apples to apples comparisons of the '15WRX being a more fuel efficient car than the 86 supported by evidence and a MechE and/or ChemE explanation if so that's unrelated to all the factors I already mentioned a few posts ago.

[JS + BRZ]

Not sure if it's my English or yours, but I don't get what you are trying to say. LOL

[abraxis]

Originally Posted by JS + BRZ

Not sure if it's my English or yours, but I don't get what you are trying to say. LOL

Well, seeing as I didn't use Ye Ole English, and all my posts make sense to me after reading them again, maybe you could try reading them again more slowly? I can help with the big bad acronyms via pm if you like. Maybe you just jumped in off the last post and didn't go back far enough? Or let me restate for you exactly what I've already said twice.

1-I have not seen any actual evidence that the '15WRX gets better mileage than the BRZ under the same exact conditions. All the evidence I can see and find says the opposite.

2-I have not seen anyone explain why the '15 WRX would get better mpg (if true) other than you saying, "that's how turbocharged cars work." Forgive me if I don't find that a scientifically valid explanation.

How's my English now? Unfortunately I can't read this for you so that's that.

So here's some questions for you since you know 'how turbocharged cars work'.

1-Why didn't Toyota put turbos on the Prius and their hybrid lineup if that's just how they work (adding mpg for free)? Don't you think Toyota would love to market an extra 10-20% improvement in mpg over the base model if they could just slap a turbo on the same sized engine?

2-Why doesn't Subaru protest the EPA/DOT certifications that unfairly diminish the fuel efficiency of the '15 WRX (like some claim here)? Seems like Subaru (and everyone else) would love to advertise higher mileage figures for the sake of marketing!

3-Under the same normal conditions (sea level environment, throttle application, tribology, etc.), a 2.0L Boxer NA should pretty much universally show better BSFC (brake specific fuel consumption) than the same 2.0L Boxer when turbo'd when under the same conditions. Now if you change fuel mapping to better tailor the turbo'd motor to both the gear ratios and driving habits of the driver (and not do the same for the NA motor), then maybe things get more interesting. This might be the case with the '15 WRX where the BRZ was tuned for window sticker EPA tests. However, none of the examples or evidence presented so far shows that's what's going on yet.

See:

http://www.bobistheoilguy.com/forums...&Number=410549

"The forced induction S.I. engines almost invariably show a poorer Brake Specific Fuel Consumption than their naturally aspirated counterparts, which, by definition is thermal efficiency.

And in the real world, which is predominantly throttled driving, the lower compression ratio gives you a lower expansion ration, and poorer efficiency under that regime also.

Pull out some BSFC maps for speed and load, and see for youself (Internal Combustion Engine Fundamentals by J.B. Heywood has such maps)."

So either the 'magic' mpg numbers are due to magic in the motor, superior gear ratios, or driver behavior. In the first two cases, the DOT numbers should bear out an advantage for the '15WRX. They do not. Extra weight and AWD are not helping with mpg either, unless those BRZ Primacies were slipping all the time resulting in wasted energy...

[JS + BRZ]

[abraxis]

[raven1231]

Can we argue about something else! Like whether or not the 2017 FRS will be a convertible or turbo, or maybe even both?

[Dadhawk]

Originally Posted by raven1231

Can we argue about something else! Like whether or not the 2017 FRS will be a convertible or turbo, or maybe even both?

The 2017 will have a turbo convertible option. The top will start moving slow, then about 4 inches and 10 seconds in will accelerate and complete in 1.0 second once the turbo kicks in.

Just don't get your fingers or head in the way in the process.

The only other change will be optional fuzzy dice.

[JS + BRZ]

Originally Posted by raven1231

Can we argue about something else! Like whether or not the 2017 FRS will be a convertible or turbo, or maybe even both?

[TylerLieberman]

Given the high compression, small displacement, and lower hp output of the BRZ, I would hope it can get better gas mileage than a WRX.

I had my FRS for a little over 2 years. Daily driven, mostly city miles, though about 30% were highway miles across country. Also had 6 or 7 days out at the track drifting (runs last all of 60 seconds). Stock for the first 12k miles. Stage 2 (headers, exhaust, tune) for the last 7k miles.

My average at the time of selling it was just over 26MPG.

This abraxis guy seems a little defensive about the FRS/BRZ. Lol wait a sec, this ft86club, of course he is.

[raven1231]

Originally Posted by JS + BRZ

Need scientific evidence! Where's my experimental design!!! Raar! Prius turbo not why is mileage be that is frs?

[JS + BRZ]

Originally Posted by raven1231

Need scientific evidence! Where's my experimental design!!! Raar! Prius turbo not why is mileage be that is frs?

You don't know how turbo works bra. Nope!

[CSG Mike]

Originally Posted by TylerLieberman

Given the high compression, small displacement, and lower hp output of the BRZ, I would hope it can get better gas mileage than a WRX.

I had my FRS for a little over 2 years. Daily driven, mostly city miles, though about 30% were highway miles across country. Also had 6 or 7 days out at the track drifting (runs last all of 60 seconds). Stock for the first 12k miles. Stage 2 (headers, exhaust, tune) for the last 7k miles.

My average at the time of selling it was just over 26MPG.

This abraxis guy seems a little defensive about the FRS/BRZ. Lol wait a sec, this ft86club, of course he is.

Therein lies the problem. The compression is TOO high. At 10.6:1 compression, the WRX is able to run much more timing advance under low (cruising) loads, and ends up extracting much more torque from the same amount of fuel.

The MPG has nothing to do with the fact that the WRX is turbo. 10.6:1 is high enough that it can extract a good amount of torque from a given combustion event, but low enough that you don't have to pull timing to prevent detonation at low load, low RPM, so that you can get more power at high RPM.

Even with the extra weight, and extra drivetrain losses of having AWD, the WRX still gets better cruising MPG.

If i'm on the throttle and driving hard, MPG drops instantly.

[TylerLieberman]

Originally Posted by CSG Mike

Therein lies the problem. The compression is TOO high. At 10.6:1 compression, the WRX is able to run much more timing advance under low (cruising) loads, and ends up extracting much more torque from the same amount of fuel.

The MPG has nothing to do with the fact that the WRX is turbo. 10.6:1 is high enough that it can extract a good amount of torque from a given combustion event, but low enough that you don't have to pull timing to prevent detonation at low load, low RPM, so that you can get more power at high RPM.

Even with the extra weight, and extra drivetrain losses of having AWD, the WRX still gets better cruising MPG.

If i'm on the throttle and driving hard, MPG drops instantly.

LOL I'm at about 800 miles on my '16 STI and I'm averaging 21mpg. 75% highway miles. Driving normally; don't baby it, but don't beat the hell out of it.

Funny seeing economy like that from a 4cyl engine. Gotta love the good ol' EJ motor.