Can you get 30+ MPG going 70-75mph?
 

Just curious who can get 30+ MPG legitimately (manual calculation - not the trip computer) doing 70-75 MPH on the highway in a M/T FR-S or BRZ.

I was able to do it early on but for some reason lately I seem to have trouble getting to the 30mpg number. Given the size of the engine and light weight nature of the car, I would think this would be rather easily achievable.

I would say yes. When i do high speed highway driving my mpg goes up a lot. Try to keep a constant speed and low rpm

Downhill... In a hurricane at your back...

Yes :)

Yes, best I've ever gotten has been 34mpg on a 175 mile highway trip where I was doing low 70s the whole way.

I do trips up and down the Mass pike on a monthly basis to the in-laws in NY. There is a 130 mile stretch that I typically do 70-80mph. The computer will calculate it to 34-35mpg but when I calculate at the pump 31-32mpg is the real number.

Depends if it's a consistent 70-75 mph.

My commute is stop and go but the average consistent speeds are about 70-75 and I average 28-29mpg. I'd like to think if there wasn't any traffic for a week I would average higher. During trips to Boston where I locked in the cruise at 74 mph I averaged over 30 mpg for the trip (if memory serves me it was about 33-34 mpg).

I got it in the middle of summer, but with the winter blend gas and the cold, I never break the 20's. Shouldn't be a problem in TX though I assume?

Easy. 365 mile round trip.

http://img.photobucket.com/albums/v4...s2impzjvm.jpeg

http://img.photobucket.com/albums/v4...sk5voecxw.jpeg

haha

Go 75mph, on a downhill decline with enough angle that you can maintain speed after putting into neutral. 99.9mpg :)

yes, I notice my mpg suffer if my tire pressure low since I don't have a TPMS

Two weekends in a row from Raleigh, NC to Jacksonville, FL (all highway, straight shot) I got 33-34. AC on full blast (it was this past summer), cruise locked in at 70 and I never hit the brakes. Haven't gone on any long trips lately, but have been getting much worse mpg since it got colder so YMMV.

It's very possible. I average 30-32 on a weekly basis traveling at 70-75 for 30 miles each way.

127mpg in the twins

ah I got cars confused, my 370 went 99.9 and the FR-S does 127.

That's because the FA20 is 27% more efficient than the VQ37VHR

27.0270270270270270270270270270% if you wanna get technical

Yes, easy. I regularly do a 100+ mile trip that's 90% freeway, cruise control between 70-75 as traffic allows. When I was calculating by hand 30-32 mpg was normal (it isn't a flat trip, several hills), I've been lazy so I just check the computer which says 32-34, pretty much the same given it's optimistic nature.

Check your tire pressures and look up if Texas has a 'winter blend' of gas, that might be the trick.

I averaged 30-35MPG on a 1800-mile roadtrip to/from Jackson WY last September. Averaged 70-85 (UT speed limit is 80!)

A few things to keep in mind:

- Check tire pressure. If you're down to 30 or lower, you could lose upwards of 10%
- Winter blend gas: since you're in Houston, your smog problems are just as bad as in LA. The winter blend here has put a noticeable dent in my fuel consumption.

-alex

On my trips between NJ and VA every few months (500) miles one way), I routinely get between 35-40mpg. I just set it to cruise. When I used to travel between PA and VA (a little over 400 miles), I was able to make it on one tank, and still had 1.5 to 2 gallons to spare

I've gotten the same numbers with 225 hankook rs-3s (extreme summer tires), the stock tires, another set of all seasons, and 215 snow tires.

got around 320 miles with about 1/8 of a tank left

I have yet to see 26 MPG anywhere.

With those with 18s or wide wheels have you noticed a large drop in MPG?

Depends on the tires... my 245/255 Toyo T1 Sport made my overall gas mileage take a 5-10% hit.

http://www.fuelly.com/driver/mav1178/brz/fuelchart

(Wheels were put on the car in late November)

-alex

I am not sure if you would count this but on a recent trip I had - taking I-5 from L.A to San Jose. I averaged about 80/85 mph and was able to achieve 85-90 miles per quarter tank - I was using 91 octane and I-5 is mostly flat for the most part - hopefully that puts things in perspective? :iono:

Also note that the entire tank is 13.2 gallons - I am not sure if the reserve tank is 3 gallons or 2, but from what I have experienced it must be about 3 gallons, which means that the tank size before the 'E' light turns on would be roughly 10.2 gallons.

I'm lucky to get 300 miles on 11.5-12 gallons. Most of the time the light comes on at ~275 miles.

The absolutely best I get was 32mpg - once, and that was when the car was new.

It's possible, i can get it to around 30-35 going 75mph at around 3.3k rpm. But this is usually due to the highway either being perfectly flat or a bit downhill. When it's a bit tilted upward I'll be looking at 26-28 to try to stay at 75. I usually just let it drop to 65 or so to keep my mpg up.

I don't know what it is about this car but the MPG hit I take when changing from 70 to 75mph is like 4mpg. At 70mph without cruise on I can get 34mpg. At 75 I get 30 or 31.

I was able to get 31mpg going ~80mph through the Panhandle of Texas and mountainous regions of New Mexico, and going through the Grand Canyon North Rim area/mountains of northern Arizona...mountains don't decrease your fuel mileage if you do it right. Use the contour of the land to your advantage and navigate traffic correctly to not get stuck behind slower vehicles turtle racing for an extended time. 70-75 mph seems worse on fuel mileage than 80-85mph...

Oh yes, I run 5-W30 and was on my track tires (Kumho Ecsta XS in stock size, aired to 40psi) as well...

I saw that once on a long continuous drive (constant speed) but I thought the MPG counter was malfunctioning. Then again regular stop and go traffic/city driving displays pathetic mpg (as expected).

29-30 mpg, with ~70% hwy commute daily.
31-33 mpg, with 95% hwy traveling out of state (cruising alot at 75-80mph).

Drag increases exponentially with speed.

That being said, I still get 34 mpg at 74 mph.

Technically, drag increases quadratically with speed, which is quite a bit better than if it were to increase exponentially.

(Sorry - my inner engineer is picky about that sort of thing)

i get over 30mpgs at 60mph-80mph

my celica gts got 34mpgs at 100mph cruising cross country, would be perfect for gumball 3000 lol

but my celica gts would get 34 mpgs at 70mph aswell lol pretty much no change in fuel economy

I can get 30mpg on the highway at 75mph with a mountain bike on the back adding more drag.

......and what country was that ...... (Nevada is not a country .... ;)) ....... :thumbup:

when did i mention nevada? i took a road trip for 1200 miles and set my cruise at 100 mph. I didnt see a soul for like 2 hours here and there. :/

Well, the only place in the the US that I've been able to cruise at over 100 mph for any extended period of time was Nevada ... :D

Allow me to re phrase the question. What country were you in that enabled you to cruise at 100 MPH ..??

Uh X^2 is exponential as well as quadratic.

A square is a rectangle but not all rectangles are squares.

He isn't wrong, you're just being pedantic. And not in a useful way, you could have at least linked some literature:

[ame="http://en.wikipedia.org/wiki/Drag_equation"]Drag equation - Wikipedia, the free encyclopedia[/ame]