zerobanger

Xyntax
you dont want to break your car in driving steady in 6th gear. You need to constantly change the revs. if you take the highway keep the revs from 3K to 5000 and dont let them stay in any rev/gear for more than a couple minutes at a time. try to hit stop and go traffic also.

grogiefrog

At least with the old 13B, I use to find that having it in too high of a gear (ie having a low RPM) actually lowered the MPG. It took more gas to get it going.

Cerestes

In my experience so far ... it doesn't matter how I drive .. crazy .. easy ... no matter what I do I get about 16 MPG ... basically if I drive at a constant speed on highway more I get better mileage like close to 19 and 20. Otherwise, it all seems to be the same. Car only has 947 miles on it though. We'll see, not that I care. I do wish gas prices would go lower though

Elara

I get much better mileage crusing around town in 6th, BUT, it's also pretty boring. So I gave up, and now my mileage is closer to 17mpg than the 20 I was getting, but I enjoy the car more. But yes, it is possible to get better mileage using 6th.

Xyntax

Thank you Elara. Nice to hear from someone who has done it already. Yes I agree, 6th gear around the city IS boring :o

I probably accelerate quick about twice a day with my 8. Going from 1st to 6th on a 45mph road. That's about as much fun as I could get while breaking-in my 8 for now. Oh, and I have fishtailed it once because the road was wet that day :D

93rdcurrent

I experience an average of 16 mpg in the city which is up from the 10 mpg when I purchased the car. It had 7.5 miles on the car when I picked it up and now I have over 5,700 miles. I am agressive with the throttle about 50% of the time and don't do a lot of freeway driving on average. When I have done long trips I get an average of about 22 mpg hwy which is up from my original 16-17 mpg. So it is getting better regardless of the fact that now the car is broken in I am driving the car harder. Maybe this is good news. Either way I still want my MazdaSpeed turbo installed :D .

zoom44

i am running a similar experiment myself right now. on my last tank "i drove it like i stole it" redline shifts in first second and third. never used 6th 5th occasionally on the highway and generally cruised between 4k and 6k whatever gear i was in. this tanki am doing the exact opposite. all shifts before 3.5k, into to 6th as soon as possible usually above 42mph. setting the cruise at 55 mph on the highway leaving large gaps between me and the cars in front. coasting (out of gear) to stops with minimal breaking. i'm at 60 miles with 3/4 of the tank left on the guage as of the trip into work this morning.

hotpot

I don't know if any one else is experiencing the same thing as I, ever since I got the RX8; I find myself constantly monitoring the trip recorder and the fuel gauge, much more than I have ever done with any other car. I might be developing a phobia here, and it's probably due to all the talk about fuel consumption that I've been reading on this forum. Sometimes I even look forward to my next fill-up so that I can calculate the mpg, damnit! It is turning into a game with me trying to beat my previous hi-score. My hi-score so far is 18 mpg. Soon I'll be driving granny style.

Xyntax

Hahah, that's funny. MPG is turning into High Score eh? Well, I will be used to getting lower MPG than advertised. I did 20 - 22 MPG on my I4 Solara because I always pull it hard up to 5K rpm (redline@6K). It was fun to feel that car go from normal acceleration to "hard-pulling" acceleration after 4K rpm. It had a VVT-i in it, kinda junior to Celica's VVT-i with Lift.

But like, I mentioned, the Solara just wasn't a toy car you could play with all the time.

93rdcurrent

You'll have fun playing with your 8 but I don't know how she'll like be called a toy.

Zeltar

I know I'll be in the minority here... but I must say this test is not good for the engine and won't really prove anything. Listen up. Gas mileage is determined by two main factors:
1) How fast you are going
2) How much fuel you are giving the engine (which is directly related to your right foot).

The whole point of a manual transmission is because humans should be smarter than the computer. Your role? To know the optimum gear to be in for the condition you are in (eg. Incline, Corner, wind, and foresight to predict change).

Let's take the obvious example - a bike. The fuel you need is equivlant to the energy you use to move the bike. We all know that it's easy to peddle in gear 1 uphill, but difficult in gear 15. And, if we're going downhill, it's actually more difficult to spin your heart out in gear 1, while gear 15 feels just right.

I had an interesting 4 Wheel drive experment with 3 jeeps in the rocky mountains of Colorado. We filled each one before the trip near the base of the road. Two jeeps used 4x4 as soon as we hit dirt. The other jeep never came out of 2 wheel drive. It was an all day event climbing from 8K to 12K feet, through a wide range of weather (sun, rain, and hail). It was slow driving on narrow roads with cliffs, hairpin turns, and water crossings. The test has relevance because in 4x4 mode, your gear ratio is much lower, giving you more control of your engine. The 4x2 mode needed more fuel to do the same thing. The final result, was that the 2 jeeps in 4x4 were within a half mpg difference between 7 and 8 mpg. The jeep that used 2 wheel drive only got about 4.5 mpg. The course was identical. The speeds were identical. The jeeps were identical models.

The moto: Use your gears, shift often, and watch your right foot.

Racer X-8

Yeah, Zeltar is right about the gearing. Use the gear that "feels" right. In the case of mpg, use the one that simply uses less gas. You should intuitively know which one that is at any given time, when to shift up and when to shift down. And the right foot is indeed the biggest factor.

I've heard that moderate acceleration uses less gas than very light gradual acceleration. Anybody gonna back me up on that?

Unless going downhill, I don't ever like to go below 2,500 rpm. I coast whenever it seems right.

Like most people, my driving is 80% routine trips that I know every bump in the road the whole way. Without even hardly thinking, my shift points, braking points, where I coast it, where I pass the slow pokes, etc, are done without hardly thinking about it. About the only thing that varries in those trips is how "peppy" I'm feeling, or how much in a hurry I am. I know when I'm wasting gas and when I'm conserving gas. Doesn't everyone?

I've not gone through a whole tankfull of nothing but conservative driving. I don't have the interest? I definitely don't have the willpower. Yeah, that's more like it...

My mileage is pretty consistant, but I can see the effects of cold weather on that last one. Cold weather really sux all the way around, doesn't it? Burrrr....Grrrrr! That last one was 15.8 Before that one, my worst was 17.1 & my average is now 18.9, highest was 21.3

60 mi @ 3/4 tank is not all that promising, but finish it out & lets see what you get...

hotpot

Update: My fuel gauge is currently at the half-way mark and I have done only 125 miles. This is not looking so good. Maybe I'll use this oppotunity to establish a new low score, which stands at 15.9 mpg.

When calculating your mpg, make sure that you fill up the gas right to the top, until you can actually see the gas. Relying on the pump's auto shut off is not accurate enough.

Racer X-8

Ooooh, I dunno about that. I was told to not go beyond that first auto shutoff because of some sensor in the tank. Try doing a search? My salesguy told me that. I don't remember the details, but he sounded like he was sure of himself on that matter.

Also, man, you're asking for a nasty mess.

I think if you stick to one particular pump, you can rely on consistancy.

ps, I think you're doing a little better than 15.9. Maybe 17 - 19? You may be right though, dunno...

Reeko

Funny,
For me I am happy if I hit 100 miles before the 1/2 point on my tank. I am getting about 14.8 MPG now.
In the summer, I was getting about 17MPG (all city type driving).
I think that cold weather and Oxygenated (alcohol 10%) gas has lowered my MPG more than driving style. I have tried to be conservative with no affect (maybe less than 1 MPG) difference.

hotpot

I find that the fuel gauge needle drops faster once you get past the half-way mark. It is not linear.

Is it really bad to fill gas up to the rim? Since I buy gas from several different stations, I think that filling the tank up to the rim every time would give the most accurate mpg. Where I live we have attendants who fill up for you, and they nvever spill any gas.

RX-GR8

i just got done doing a trip to ocean city, nj via the AC expressway. round trip 120 miles. i got about 20 MPG. i used cruise as much as possible at 66 MPH in 6th gear. it was good to know i can still get 20+ MPG highway because most of my driving is city and i get 14-15 MPG.

Kagero

I was surprised yesterday. I found myself out in the middle of nowhere and the low fule lite came on. So I took it easy, not sure where the next gas station was. Well when I did get to fill up the gage was one notch below E (if there was one it would be on it). It only took 13.54 gals to fill it and I put all I could get in. So I still had over 2 gals left! Anyone find this with yours?

hotpot

My low-fuel light comes on around the 1/8 mark. Haven't risked to find out how low it will go until it dries up.

When it's filled up, the needle is about 2 notches above F.

I find the fuel gauge a bit erratic. At certain points the needle drops slowly and sometimes very fast, under the same driving conditions. I've also noticed the needle dropping a notch overnight.

itsallaboutgary

hey guys...i have 150 miles and im at half tank so far...so see if i can make it to 290 or even 300! this is with 70% highway =)

Xyntax

Update: Sucks. I refueled yesterday after getting the Empty light. Filled up 13.5 gallons at 196 miles on the trip meter.

I must admit, I have been revving it higher than I planned. Oh well. Hopefully, I wont be one of the people who complain getting 14MPG all the time.

johncalifornia

Xyntax, if you're serious about lugging your new RX-8 around town in 6th gear to get better fuel economy, e-mail me and I'll take if off your hands.

I'm shopping for an RX-8 and buying yours would be like rescuing a puppy whose owner locks it in a closet all day and kicks it when it cries. I live in the Bay Area and I'm serious!

93rdcurrent

John be fair to Xyntax. He is in his break-in period and already stated that this is not how he planned on driving it all the time. He just wanted to experiment with his car to see if there was a way to meet or come close to the EPA standards posted on the door when he purchased it. Most of us are a little frustrated with that fact. I know that my M3 was getting the EPA listed gas mileage and I can find no reason why my 8 shouldn't as well. I drove that M3 "like it was stolen", to borrow from several posts. I am not asking Mazda to turn the 8 into a Prius I just want what I was promised. Oh and more hp too. Well and maybe a turbo would be nice...

hotpot

Don't rejoice so soon. As I mentioned before, the needle seems to drop faster below the half-way mark. And the gauge is not all that accurate. Let us know anyway if you get a new hi-score.

johncalifornia

93rd, the break-in period is the worst time to lug a new engine, esp. a rotary one. (Lugging is driving at low revs and large throttle openings.) I'm surprised you got away with it on your M3 -- they have a lot of engine problems I hear -- but it's even more risky with a low-torque rotary.

People think that low revs mean being easy on the engine but this isn't true. It's low LOADS that are important. The engine works much harder at low revs and big throttle openings than it does free-revving at smaller throttle openings.

During break-in you should free-rev up to the maximum RPM permitted by the manufacturer, staying in lower gears and using minimum throttle. This means driving around town in second gear. The seals will seat and the engine will adapt to its rev range.

After it's broken in, warm it up well then drive it hard. The engine will last forever if you change the oil frequently and use premium gas.

About turbos -- this car doesn't need one, just a chip to restore its missing 20 hp. A turbo would seriously compromise its driveability. If you drive an 8 like it needs to be driven (keep the revs UP), it will not be short of power at 250 hp. Hell, it's quite acceptable stock.

If you wanna drag race, get a Mitsu Lancer Evo. Drag racing an 8 is a bad idea of a bunch of reasons, not the least of which is that you will lose to inferior cars nearly every time.

- johncalifornia, rotaryhead since 1970 (Mazda R100)