Notices
RX-8 Discussion General discussion about the RX-8 that doesn't fit in one of the specialty forums.

How to get BEST MPG on Rx8 (~20-22mpg)

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 03-13-2013, 04:14 PM
  #101  
Registered
iTrader: (4)
 
alnielsen's Avatar
 
Join Date: Aug 2004
Location: Buddhist Monastery, High Himalaya Mtns. of Tibet
Posts: 12,255
Received 6 Likes on 6 Posts
Coasting in neutral, the engine needs gas to keep it running. Coasting in gear, the engine is kept turning by the momentum of the car. Gas isn't required and the injectors are turned off.
Old 03-13-2013, 04:30 PM
  #102  
Registered
iTrader: (7)
 
DinSum's Avatar
 
Join Date: Dec 2012
Location: London, ON
Posts: 123
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by paimon.soror
Why else would you coast? Are you telling me that you coast on the highway in neutral? Are you stupid?

Btw, go to skip barber and take a lesson ... you will be surprised how many times you actually make use of (or lack there of) the neutral gear.

LOL, no i'm not stupid, are you?

Most of my driving is on a 90km/h road with many sets of lights all the way to work and back home everyday

Anyways people can listen to who they want, i just wanted to throw my two cents in there.
Old 03-13-2013, 04:39 PM
  #103  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 239 Likes on 109 Posts
There are different times to use different methods of car control, and safety will always trump gas mileage. You aren't going to just engine decel in 6th when someone ahead of you panic-brakes (extreme example).

Din, all they are saying is that in-gear engine decel is always less gas consumption than neutral. Always. Greater than zero will always be...greater than zero.

All you are saying is that sometimes the overall net better mileage might not be staying in gear.

Neither argument invalidates the other, because safety will always overrule efficiency.
Old 03-13-2013, 04:56 PM
  #104  
Registered
iTrader: (7)
 
DinSum's Avatar
 
Join Date: Dec 2012
Location: London, ON
Posts: 123
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by RIWWP
There are different times to use different methods of car control, and safety will always trump gas mileage. You aren't going to just engine decel in 6th when someone ahead of you panic-brakes (extreme example).

Din, all they are saying is that in-gear engine decel is always less gas consumption than neutral. Always. Greater than zero will always be...greater than zero.

All you are saying is that sometimes the overall net better mileage might not be staying in gear.

Neither argument invalidates the other, because safety will always overrule efficiency.
Thanks RIWWP

You are one of the few people on these forums that doesn't bash somebody when he disagree's, we need a lot more people here like you man seriously, i like all you have done for the rx8 community your awesome bro thanks
Old 03-26-2013, 01:15 AM
  #105  
Registered
 
ahardy25's Avatar
 
Join Date: Mar 2012
Location: spartanburg, SC
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
during city driving i shift at the notch before 3 rpm and i try to keep the car rolling. and on the high way i drive around 65-70mph. i do see better gas milleage around 21-22 mpg but i reach my destination slower lol
Old 03-26-2013, 03:21 PM
  #106  
Yellow looks faster.
iTrader: (1)
 
Wolfe's Avatar
 
Join Date: Jun 2012
Location: North NJ - Utah - Arizona
Posts: 445
Likes: 0
Received 0 Likes on 0 Posts
I find that the best gas mileage is obtained from not driving the car as much as possible. That way, when you do drive the car, you get to drive it as it was meant to drive. But for "engine health" I shift around 3.5k and then when the car is warm, around 4k. My mileage does not do so well.
Old 03-26-2013, 03:44 PM
  #107  
Registered
 
CRO8TIA's Avatar
 
Join Date: Nov 2009
Location: Adriatic Paradise
Posts: 596
Likes: 0
Received 0 Likes on 0 Posts
Drive it like you stole it, it's meant to be driven hard, not to sound like an a**, but if you want good fuel economy, buy a diesel .
Old 03-26-2013, 04:10 PM
  #108  
Flame On!
iTrader: (4)
 
1.3_LittersOfFurry's Avatar
 
Join Date: Jan 2011
Location: New Orleans, La
Posts: 1,897
Likes: 0
Received 4 Likes on 4 Posts
How to get BEST MPG on Rx8 (~20-22mpg)

It's very simple, really...
Buy a second car, preferably a econo **** box, for daily driving.


Driving a rotary in "econo" mode (low rpms, coasting, ect..) is not only boring as hell and defeating the purpose of having a rotary. It's also not very healthy for it in the long run.

The more you mod it, the more your mpgs will decrease, but the bigger your smile will be.
Which is worth every dollar at the pump.
Old 03-26-2013, 08:05 PM
  #109  
New Member
 
ruthlessfc69's Avatar
 
Join Date: Mar 2013
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
the rx8 is a great car but not for a daily. it wasn't made to be eco friendly. so if u want a better mpg get another car.


Posted from Rx8club.com App for Android
Old 04-11-2013, 02:04 PM
  #110  
Registered
 
Silverdollar's Avatar
 
Join Date: May 2012
Location: Ashburn, VA
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Exactly my thoughts! The bottom line is this car needs to be "run hard". By that I mean when you shouldn't be shifting out of 1st until around 3200, and take 2nd up to 6000, run 3rd at 5300 and let it just rock up to 8000 if you want. The engine will perform if it is pushed. It redlines way up there for a reason!
Old 04-11-2013, 03:38 PM
  #111  
Registered
 
vanslam's Avatar
 
Join Date: Feb 2012
Posts: 24
Likes: 0
Received 0 Likes on 0 Posts
Its all in perspective, my daily driving RX8 gets way better mileage than my weekend Bentley GT, which is 10mpg in the city and 16mpg on the highway and 12 mpg average.
Old 04-11-2013, 07:22 PM
  #112  
Registered
 
smedly's Avatar
 
Join Date: May 2008
Location: Henderson,co
Posts: 25
Likes: 0
Received 0 Likes on 0 Posts
If I want high mpg I drive my 98 civic . If I want to get high mpg and grin like I do driving my RX8 I ride my Hayabusa . I knew what I was getting into BEFORE I bought my RX8
Old 04-12-2013, 07:18 AM
  #113  
Moder8
iTrader: (1)
 
04Green's Avatar
 
Join Date: Aug 2009
Location: Oviedo, Florida
Posts: 2,578
Received 49 Likes on 31 Posts
One we missed is actually knowing the mileage you are getting. An UltraGauge, or like device, Ultra Gauge is just cheaper, did wonders for showing me what I was doing real time, as opposed to only when I fill up the tank. Like all of these you need to calibrate the MPG, but that is basically just putting in how much gas you really used per tank for the first several tanks. I am sitting at 22 right now, up from 20.5 before I tuned it up. Seems I skipped a year on coils... Oops. MPG popped up pretty darn fast after the new coils.

Finding out that 76mph on the highway gets 2 MPG less then 74 was quite interesting. And, closed loop seems to do a bit better than open loop. Also, I can actually watch the tires warm up on the MPG.
Old 09-03-2014, 06:55 PM
  #114  
Registered
 
dricampbell's Avatar
 
Join Date: Aug 2014
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
My plan to improve mpg was simple - Get a motorcyle/scooter for short inner-city trips (150mpg and reasonable fun).......

And let the rx8 loose on the highway commute to work.

Simples.

PS - if put off by low MPG this is the wrong car for you.
Old 09-03-2014, 08:04 PM
  #115  
Registered
 
ken-x8's Avatar
 
Join Date: Aug 2006
Location: Northern Virginia
Posts: 5,027
Likes: 0
Received 5 Likes on 5 Posts
...Get a motorcyle/scooter for short inner-city trips...
Brilliant! My approach to fuel economy was the discovery that I could get away with telecommuting one or two days a week, instead of driving into the office. Immediate 20% to 40% boost.

Ken
Old 09-04-2014, 10:11 AM
  #116  
Moder8
iTrader: (1)
 
04Green's Avatar
 
Join Date: Aug 2009
Location: Oviedo, Florida
Posts: 2,578
Received 49 Likes on 31 Posts
++ Ken, add a car pool day and even more savings...
Old 09-05-2014, 12:49 AM
  #117  
New Member
 
Kenshi's Avatar
 
Join Date: Sep 2014
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by DinSum
when you leave the car in gear yes it uses no gas, but it will slow your car down three times as fast as being in Neutral so the only time its more benifitial to leave it in gear is if you are doing city driving and you have to stop a lot without much warning. So try this, go 60mph then let go of the gas and see how far you get before it stops, you wont get nearly as far as being in neutral especially if the road has a slight decline.but the disadvantage of being in neutral is your engine uses a little bit of fuel to idle, but it uses very little fuel when idling compaired to actually driving so after much testing and compairing with torque mpg readings its better to pop in neutral when going fast and you see the red light far ahead of you, then pop it in 6th gear right before getting to the red light to save a little more fuel.
You're absolutely right, the extra distance will more than make up for the tiny amount of fuel you're using. Plus it causes less wear on your engine (although as long as you leave it in a high gear, there won't be that much wear). However, you have to coast a hell of a long way to take advantage of this. I don't think many people have the patience to coast for half a mile, certainly not me. If you do, then I hope I never get stuck behind you.
Old 09-05-2014, 07:24 PM
  #118  
Registered
 
ken-x8's Avatar
 
Join Date: Aug 2006
Location: Northern Virginia
Posts: 5,027
Likes: 0
Received 5 Likes on 5 Posts
Originally Posted by 04Green
++ Ken, add a car pool day and even more savings...
But I'd have to shell out for swimming lessons for the 8...

Ken
Old 09-07-2014, 12:48 PM
  #119  
Registered
 
khaira93's Avatar
 
Join Date: Oct 2012
Posts: 69
Likes: 0
Received 0 Likes on 0 Posts
I get like 300KM per tank if I drive normally, less if I drive like it's truly meant to be driven.

Rough life.. but tis fun!
Old 09-07-2014, 02:51 PM
  #120  
dag
Registered
 
dag's Avatar
 
Join Date: Jan 2004
Location: NJ
Posts: 371
Likes: 0
Received 0 Likes on 0 Posts
Wow - strong debate.

I've owned my 8 now for 10.75 years. I've driven at times with a lot of highway driving, at times with mixed driving. I generally make a mental calculation of mpg with each fill up. With the light on, a fill up is close to 14 gal. A tank of gas for me has ranged from 225 mi and grows to 250 mi + if I do pure highway driving. So best case scenario, I can save around $5/mo by taking measures to save gas. I know everyone has their own situation, but for me, I'll take my red line beep and spirited driving. I bought the RX-8 to have a sports car experience. If gas mileage was important, the 8 would never have been on my list of cars to buy over 10 years ago. A Civic would have been my choice. I cringe every time I hand over my credit card to the gas man, that changes the moment I put my foot on the gas pedal.

dag
Old 09-07-2014, 02:53 PM
  #121  
Moder8
iTrader: (1)
 
04Green's Avatar
 
Join Date: Aug 2009
Location: Oviedo, Florida
Posts: 2,578
Received 49 Likes on 31 Posts
Like ^^^

I track gas mileage for engine health. It is the first thing to suffer.
Old 09-07-2014, 03:44 PM
  #122  
dag
Registered
 
dag's Avatar
 
Join Date: Jan 2004
Location: NJ
Posts: 371
Likes: 0
Received 0 Likes on 0 Posts
It's been tough for me to determine if my gas mileage is down because of whatever the reason or because my driving habits have changed (last 3 years I pretty much have short drives to a train station). I recently tuned up the 8 and cleaned the MAF, and that didn't really improve gas mileage, but I'm OK with that. If my engine goes, well I can only sit back and say it's been a good run I mean how many other cars would I expect 11 years or more out of it?

And for those that think my above statement may be trolling, it's not really my intention. I think what I'm trying to relay is drive the car the way it's meant to be driven. I don't think there's anyone out there that would ever say the 8 was meant to get good gas mileage. It's not like the HP blunder Mazda made when it first came out. If a mistake was made in your choice, whether financially or performance expectations, well you have to figure out for yourself. If someone is able to make a legit thread that can say I can enjoy my 8 and get better mileage by doing X, I'm listening, but if the thread is providing tips on how to drive the 8 like a Geo Metro, well that's just a waste of server storage space.
Old 09-09-2014, 03:14 PM
  #123  
Registered
 
Vader76's Avatar
 
Join Date: Jun 2005
Posts: 52
Likes: 0
Received 0 Likes on 0 Posts
When I first got my car in 2005 I'd get around 340 KMs per tank. That dropped to 290KMs when my engine was dying. After the engine was replaced and I installed BHR coils and wires, I get around 400KMs per tank.
Old 09-11-2014, 08:51 PM
  #124  
Registered
 
colinshark's Avatar
 
Join Date: Sep 2013
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
I used to hypermile my NA RX-7, and could do 24mpg. It's even harder with the RX-8. Best is about 19 mpg.

I just run it like it's supposed to be, and I'm happy with 16mpg. Just accept that you have a fun car, and spend some more on gas.

I can't let go of that notion. Driving an RX-8 slowly and gradually, all over town is just really, really sad.
Old 09-11-2014, 08:55 PM
  #125  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 239 Likes on 109 Posts
If that 19mpg is an in-town best, then it's good.

If that 19mpg is a highway best, then you would gain quite a bit by fixing what's wrong.


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: How to get BEST MPG on Rx8 (~20-22mpg)



All times are GMT -5. The time now is 06:15 AM.