please don't flame me for another mpg thread...........

The car is brand new, got 500 miles on it now and still treating it like a virgin during its break-in.

I never shift above 5-6000 rpms and generally try to shift below 3800rpm but I'm still getting just shy of 16mpg....My driving is generally somewhat busy highways; regular movement but frequent gear changes; average speed around 60mph...........

Will this get better as the engine is broken-in? Do I need to demand anything from the dealer? Are there any flashes that will help?

Believe me, I've read everything here regarding this overly expresssed sentiment but this is worrying me greatly.......................Hell, I haven't even stomped on it yet and I'm still watching the fuel gauge drop like a rock...................

 

I may be way off but i remember reading that an engine's most efficiant moment is at peak torque. I assume the rx-8 get bad mileage becuase the peak is waaay up in the rpm range.

 

Take it out for an extended drive on a freeway over the weekend and it should climb dramatically (keep it under 74mph). Similarly, take it on some back country roads and do some running in the 4000-6000 rpm range. Your milage should climb as well.

If it climbs to just shy of 20mpg, you're baby is normal.

Mike

 

Mine got better after the engine broke in a bit. When i first got it it had like 500 miles on it and the gas milage sucked haha. Now its at about 18-19 with a few redlines here and there.

 

it is my understanding that the second set of injectors kick in at 3800. So you guys are telling me that I may be doing the exact wrong thing by trying to keep the revs way down??

Frankly, I'd love to drive it like I stole it, but since I'm already trying to be good during her break-in period, I'm being way tooooo good.........

 

Stop driving like a grandma and the mileage will improve.

 

Yeah, I get the bad mileage too even if i keep it at about 3.5k. The good news is that I get about the same mileage even if don't really worry about it and drive fast.

Mpg should go up after break in, it took me about 10k miles to get to about 17 from 13mpg. Also, I get 21 mpg with premium but with how much premium costs I'm not saving money.

 

Its more complicated than that, it was found that its engine load and rpm. Crusing at 4.5k doesnt mean that the secondary injectors are working. Just have fun driving, dont think you need to keep it below 75 on the interstate. After several roadtrips, I found mpg to stay pretty consistant 22mpg, woot! while driving 65, 70, 75, and 80.

 

What I am really saying is stay away from traffic, red lights and sitting and idling it. Never go through the drive-thru at Taco Bell. The gas you burn in line will cost you more than the food.

Mike

 

Only 16 mpg!?
Thats too bad....
I get 10 or 11 mpg...

I'd trade mpg with you anytime...

They say gas milage improves with time.... I've got 9,000 and it still sucks.

 

The enemies of mileage are;
Stop and go traffic (Idling is really bad for rotary mileage)
Heavy foot (the revs don't hurt you as much as the throttle position)
Cold temperatures (my mileage is about 20% lower in winter than in summer)

 

check your tire pressures and how clean your air filter is.

 

You are waaaaay off. Take a look at a few dyno sheets. The torque curve....well...it really isn't like a curve, it's more like a shelf. It's pretty damn flat.

 

I'm thrilled !

After 4200 miles of 12 to 15 MPG in mixed city / highway driving, I decided my '05 6MT was ready for a serious road trip. I now have just over 5000 total miles on the car.

Voila ! First leg was LA to Bishop CA. 260 miles, one mountain crossing otherwise mostly level cruise at altitude of 3,000 to 4,000 feet, average speed 75 MPH. Fuel consumed: 12.2 gallons which equals 21.3 MPG.

Second leg was Bishop to Mammoth Mountain, back to Bishop, then to Las Vegas NV. 310 miles, altitudes up to 7,500 feet incluiding two mountain passes, twisties and heavy foot at speeds of 55 to 70 MPH first 150 miles then cruise into Vegas at 75 to 85 MPH. Fuel consumed: 17.3 gallons which equals 17.9 MPG.

Final leg was Vegas back to LA. 275 miles, two mountain crossings otherwise boring desert with some hills. Speed 73 MPH on cruise control, no stops other than agricultural check station outside Barstow. Fuel consumed: 12.6 gallons which equals 21.8 MPG.

I was burning 89 octane fuel which was $3.55/gal in Mammoth Lakes CA and $3.30/gal in Beatty NV, so this "great" fuel economy was a very pleasant surprise. Now we'll see how it does back here in So. Cal. traffic.

RX-8 also seemed to have more power than ever on the trip, even at the high altitudes.

Maybe she is broken in now.

 

More power is due to the long running times and the ECU and oil pressure really getting consistant and letting it open up.

Jeez! 3.55 is nuts for regular. And I thought the 2.90 over here was highway robbery.

 

Stop driving like Gran' Ma.....
At least you'll have an excuse. hehe

 

05 or 06? just wondering if there are any changes

my break in was nice and peachy at 16 too .. then i started driving and 12-13 seems to be the norm .. look at it this way at least insurance is cheap

 

LOL....is there a way to set browse settings to "ignore anything with GAS in the topic". Hate to say it, but these things suck the gas. Yeah...I'm a *****...

 

I know your pain. Here is what I have experienced. The car is a 05 with 1,800 miles on it. The first 600 I drove it in break in mode and got just south of 13mpg. This was in the middle of Winter 20 degrees. It is now around 65 degrees and I am driving the car more aggressively. My driving is all Chicago city driving and I average just south of 12 mpg. As someone else said no matter how hard I drive it, it still is in this 11 to 12 mpg range, which sucks. A guy here at work drives my same route to work and he has the large Lexus SUV V8....he gets 14 miles per gallon. On the highway I get 20 to 22 mpg at 75mph.

 

I bought and expected the worst after reading the forums for two years.
I have just over 1200 miles on my new 05 and other than the first tank of gas (from 100 miles to 300 miles on the odom) I consistently get 21 mpg.

Guess I got lucky and did a good hard break in.

 

my car gets 18-20 (19mph most tanks) city, I drive to from work in traffic/city streets and dont use the highway at all (anymore) and am getting near 20mpg.............I drive the car and have fun, use the rpm frequently.

If I feel like it, I can get as much as 22mpg driving the same route i normaly get 19mpg......how?

I shift at LOW rpm, im in 6th gear by 35mph!!! That nets me 22mpg..........pretty good considering even on the highway with cruise control I cant get over 24mpg.

Most of the time I redline the car in the first 3 gears every drive I take, at least once.

I shift at around 4-5k rpm and cruise at about 4k rpm....so i have the tq there when I need it.

 

Oops - a typo (honest!) - sorry. My car is an '05.

In-town mileage is noticeably better since that road trip. I'm estimating 18 MPG... much improved from about 14 before.

 

Consistent 17 mph with mixed driving through 8000 miles on my '06. One all-highway tank of 20 mpg.

 

Geez sounds like you guys are taking a beating. I just bought my 05 brand new and it had 23 miles when I took delivery 2 days ago. Unfortunately I had to drive it home on the highway since I bought it 300 miles out of town.

I left the dealership @ 23 miles with a full tank of gas and made it back to Dallas running on empty with the odometer at 310 miles so I got 287 miles for a tank (about 90% full) figure 12.5 gallons so I got right at 23 mpg.