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Vasichko 07-28-2007 10:45 PM

Ways to get better MPG?
 
Ive had my car since 7/7/07 and am looking for ways to get better MPG. I am averaging about 180 - 200mpg. Of course this is going from a full tank and when the gas light turns on.

Just had the leading plugs and coils swapped out at my local Mazda dealer.

Money isnt a problem for the gas, but of course when anyone can save a bit of money here and there it helps.

DarkBrew 07-28-2007 10:53 PM


Originally Posted by Vasichko (Post 1991272)
I am averaging about 180 - 200mpg. Of course this is going from a full tank and when the gas light turns on.

:ftw:

over 180 MPG and you want more!!... I'd be happy to get 20 MPG

Seriously, what year is your car, how do you drive, City, Hyw?

No info, no answers possible.

Searching mileage will help.

Vasichko 07-29-2007 02:22 AM

05'

City Driving 0 - 90%

I would say I take it to 9k at least once a day only because I dont want carbon build up.


Originally Posted by DarkBrew (Post 1991277)
:ftw:

over 180 MPG and you want more!!... I'd be happy to get 20 MPG

Seriously, what year is your car, how do you drive, City, Hyw?

No info, no answers possible.

Searching mileage will help.


Raptor2k 07-29-2007 04:08 AM

18-20 mpg (I'm assuming that's what you mean) for 90% city driving is pretty damn good. Whatever you're doing, keep doing it. There really isn't any practical way to significantly alter your gas mileage. But don't forget to have fun with the car and drive it like it was supposed to be driven every once in a while.

RX8Maine 07-29-2007 06:49 AM

Actually, if he fills up when the light turns on (which for me is about a 13.5 gal fill-up), then he is actually getting 14mpg. there is a pretty broad range of mileages that people get, and I am not sure you are out of the ordinary.

I do better than that in similar driving, closer to 16mpg at the worst, but I seem to have been blessed. On our spring Adirondack run, I averaged about 3mpg better than everyone else in exactly identical driving conditions, and I had favored power over economy, keeping the car in lower gears than I would on a daily drive.

TheDosDog 07-29-2007 09:58 AM

Coming back from Reno yesterday I was at 270 miles when I refilled with over a quarter tank left. Turned out to be close to 28 mpg. I discovered the secret to better mileage. Always drive down hill :)

expo1 07-29-2007 10:11 AM

6th gear. The more time you spend in that gear the better the MPG.

Vasichko 07-29-2007 11:43 AM

I try that. Oh well, maybe exhaust and intake would help a bit?


Originally Posted by expo1 (Post 1991547)
6th gear. The more time you spend in that gear the better the MPG.


DarkBrew 07-29-2007 11:45 AM


Originally Posted by Vasichko (Post 1991610)
I try that. Oh well, maybe exhaust and intake would help a bit?

My cat-back seemed to hurt my mileage a bit but it might be because I'm listening to the engine more...:)

killinghall 07-29-2007 11:52 AM

the 8 loves the freeways so try to take them if the situation allows.

been hitting about 20-21 mpg for the last two tanks, 75% highway drving. or about 8.5 - 9.0 km/l as google will have it.

oh yeah, a light foot helps too, but that's not possible all the time!

chickenwafer 07-29-2007 03:48 PM

^I agree. Highway driving is when the 8 gets wayyy better mileage. For me at least.

I notice when I troll in the city I get around 210 a tank. On the freeways I can get over 300. I made a trip a month ago to Vegas and got over 330 to a tank.

Jax_RX8 07-29-2007 04:07 PM

A clean engine is an efficient engine.

Carbon/Sludge/Varnish and other gunk on Injectors, Plugs, Rotors, Intake ports, Exhaust ports, and Catalyst all contribute to a less efficient engine - and the rotary, due to it's rich fuel mixtures and oil injection, generate lots of it.

Try this.

skhmund 07-29-2007 04:12 PM

i set cruise to 65 n i redline once everytime i drive n i still get about 310 miles to the tank, mostly hwy driving

ModestoRX8 07-29-2007 04:12 PM

at what point should I ask my delaer to look at my car? I currently drive 99% city, back and forth to work. The fastest I tae it is 45mph or so. and the commute only takes about 10 minutes a day each way... i am currently only getting 160 - 180 miles before I need to fill up... Closest I can figure I am around 12 MPG. Once a week or so i do take it out on the highway and wind it out, just cause its fun. :)

I have only had this car for 3 weeks and am looking forward to my first long trip, but I want to know if I should ask the dealer to look at it now, or wait till a nice long trip to see what happens....

Jax_RX8 07-29-2007 04:34 PM


Originally Posted by ModestoRX8 (Post 1991903)
at what point should I ask my delaer to look at my car? I currently drive 99% city, back and forth to work. The fastest I tae it is 45mph or so. and the commute only takes about 10 minutes a day each way... i am currently only getting 160 - 180 miles before I need to fill up... Closest I can figure I am around 12 MPG. Once a week or so i do take it out on the highway and wind it out, just cause its fun. :)

I have only had this car for 3 weeks and am looking forward to my first long trip, but I want to know if I should ask the dealer to look at it now, or wait till a nice long trip to see what happens....

Extreme City Driving (which is what you are doing) will always get very low mileage - this is normal.

Also, your in "warm-up" mode for most of your driving, contributing to the low MPGs as well.

Brettus 07-29-2007 04:36 PM


Originally Posted by ModestoRX8 (Post 1991903)
and the commute only takes about 10 minutes a day each way...

there is your problem - the motor never really gets warmed up enough to be efficient . You bought the wrong car for this kind of treatment - not only will your fuel consumption be crap but your motor will carbon up very quickly .

killinghall 07-29-2007 07:18 PM

At the 1/4 mark, my last 3 tanks have covered 250miles/400km. Looks set to be the same this time!

Given a full tank I could possibly cover another 150 more!

:)

Nopstnz 07-29-2007 07:51 PM


Originally Posted by Brettus (Post 1991934)
there is your problem - the motor never really gets warmed up enough to be efficient . You bought the wrong car for this kind of treatment - not only will your fuel consumption be crap but your motor will carbon up very quickly .

meh.. my usual commute is only about 7-8 minutes a day and i average 19+

h-khunterkiller 07-31-2007 04:25 PM

follow a semi as often as you can, you ll have less drag from the wind. 20 to 40% increase in miles

Jax_RX8 07-31-2007 07:07 PM


Originally Posted by h-khunterkiller (Post 1995138)
follow a semi as often as you can, you ll have less drag from the wind. 20 to 40% increase in miles

And a well dinged up nose piece with busted oil coolers and AC condenser.

h-khunterkiller 07-31-2007 07:16 PM


Originally Posted by Jax_RX8 (Post 1995296)
And a well dinged up nose piece with busted oil coolers and AC condenser.

i said a semi not a cargo truck. they will pick up as much rocks as any car, plus you should have place a grill in front of them by now

User24 07-31-2007 07:17 PM

There are a couple of very good "ways to increase MPG" threads available; I recommend you look them up.

In day to day driving, expect 40 miles per quarter-tank mark. That comprises a mix of 5 mph, 25 mph, 45 mph, and 65 mph zones, along with getting stuck in merging traffic on the trip home during rush hour.

During multi-state relocation travel, at 85 mph, expect 60 miles per quarter-tank mark.

"40-60 miles per quarter tank" is a phrase that covers almost all previous and future "I got such and such" mpg responses and quotes. With the following exceptions:

1. The guy whose tach got locked at 9500 and wouldn't go down for some reason.

2. The guy who bought an RX8, but found out it had no motor in it and has to push it around everywhere, much like a shopping cart.

Almost anything you do will land you somewhere between 40-60--the result is already known, the exact number is for you to find out. People keep hoping to get a magic tip that will bring them out at 80, but there's no such thing.

Realistically, you can hope to achieve 16 mpg in day to day driving, with the use of 5 x 35. That is, be in 5th gear by 35 mph. It took me 2 years to learn that, and now you know everything I do about fuel efficient rx8 driving.

TeamRX8 07-31-2007 07:24 PM

trade it in for a Prius ...

tiggerlee 07-31-2007 07:33 PM


Originally Posted by TeamRX8 (Post 1995315)
trade it in for a Prius ...

That's crazy talk!

I say the best way is to drive downhill only with the wind at your back.

If that doesn't work mount a mast and slap a sail on that bitch.

otakurx 08-01-2007 08:50 AM

I average 20mpg in the city and 22-23mpg on the highway. I run 10-30 Castrol GTX, now have been running FD plugs for 4k miles, a K&N drop in, stock wires (just burned out on me) and almost always get Irving fuel.

I am thinking about going to better wires soon and the improved ignition module to see if that will help any.

Vasichko 08-01-2007 09:51 AM


Originally Posted by TeamRX8 (Post 1995315)
trade it in for a Prius ...

Or for a GTO, STI, Evo which all get better gas mileage, more hp more torque...

Vasichko 08-01-2007 10:50 AM


Originally Posted by casedogg (Post 1996139)
i redline my car all the time in city driving, and on the freeway average about 85 mph and i am getting 70 miles to quarter tank mark about 280 miles per tank, and about 70% of my driving is city. I always reset the trip mileage when i fill my tank up so i can see how many miles i'm getting

I just filled up, last tank I got a total of 154.7 miles and this is driving 16 miles with the gas light on.

This tank had 0 redline, all shifting done between 3000-3500 rpm. Driving slow, people passing me up after lights.

Wondering what the issue is???

Nubo 08-01-2007 11:06 AM

http://www.gassavers.org/

Vasichko 08-01-2007 12:00 PM

Im not looking to get 350 out of a tank. Hell I would be happy with 230 - 240 to the tank at this point.


Originally Posted by Nubo (Post 1996178)


steven000e 08-01-2007 12:20 PM


Originally Posted by expo1 (Post 1991547)
6th gear. The more time you spend in that gear the better the MPG.

^ This is not TRUE at least for me...
I only use 6th gear if i am going above 75m/h

I have been driving that way for the past year and I am getting between 19-22 miles per galon mixed driving
I get about 290 miles per tank

I used to drive in 6th gear before at speeds around 50 miles per hour :Eyecrazy:
which is bad for the engine according to my dealer..
the more you use 6th gear in low rpm's the more gas the car drinks... at least thats how mine is!!
I used to get anywhere from 180-220 miles per tank before...

Vasichko 08-01-2007 01:42 PM

So what gear do you leave it in at 40-50?


Originally Posted by steven000e (Post 1996291)
^ This is not TRUE at least for me...
I only use 6th gear if i am going above 75m/h

I have been driving that way for the past year and I am getting between 19-22 miles per galon mixed driving
I get about 290 miles per tank

I used to drive in 6th gear before at speeds around 50 miles per hour :Eyecrazy:
which is bad for the engine according to my dealer..
the more you use 6th gear in low rpm's the more gas the car drinks... at least thats how mine is!!
I used to get anywhere from 180-220 miles per tank before...


steven000e 08-01-2007 07:08 PM


Originally Posted by Vasichko (Post 1996462)
So what gear do you leave it in at 40-50?

my drives are 70 highway 30 city

so
I use 5th G between 56 to 74
4th G between 38 to 55
3th G between 29 to 37

^ that is about my normal driving! I use low G now and then to get up to redline...

again this is what works for my car!
I get good mileage driving this way!

PhotoMunkey 08-01-2007 10:48 PM

It seems to me, judging from the responses on this thread to gear selection vs speed, that the engine is responding to the throttle position sensor MORE than anything else.

I.E. If you drive at 50 mph in 6th gear, you're lugging the engine, but tipping in a little farther on the gas pedal because the engine is out of its "sweet spot" People who are using 4th and 5th at 50 are keeping the engine spun up, but have the throttle at less angle.

My own experience seems to confirm this as I can drive my car sedately through town, in 5th at 35 or 6th in a 60 mph zone, and get 13-15 miles per gallon, but can wail on the engine in 3rd and 4th gear exclusively on a winding canyon road, and get 20 MPG! Also, if I cruise along at 73-74 mph, I can get around 22 MPG, but once I go up over 75 and near 80, the dreaded "extra fueling" kicks in and the mileage drops off to around 18-19. I've tracked this over 12,000 miles, since the very first tank of gas!

PhotoMunkey 08-01-2007 10:50 PM


Originally Posted by otakurx (Post 1996012)
I average 20mpg in the city and 22-23mpg on the highway. I run 10-30 Castrol GTX, now have been running FD plugs for 4k miles, a K&N drop in, stock wires (just burned out on me) and almost always get Irving fuel.

I am thinking about going to better wires soon and the improved ignition module to see if that will help any.

What's the significance of the FD plugs? Colder temperature range? What's the octane rating of the fuel you're using? Thanks!

Razz1 08-01-2007 11:03 PM

Don't use FD plugs.

rotarypower88 08-04-2007 01:50 PM

ive been getting horrbile gas mileage since i bought my car about a week ago, about 150 to a tank which is about 10mpg, it has 52k on it and im sure it hasnt had a tune up yet. so im assuming that is going to help out. but of course like i said i also just bought it so i have been running it pretty hard. when does everyone usually do their tune ups, cuz i know my rx7 is very picky about its spark plugs

Georgia8er 08-05-2007 01:17 PM


Originally Posted by Nubo (Post 1996178)

Looking through those forums, there is an extreme amount of misinformation on there.

otakurx 08-06-2007 10:29 AM

I run 89-91 octane normally, what is the big deal with the FD plugs, I chose them because they were less expensive and I couldn't find plugs for the 8 when I needed them. No place around my house carried them. I have put about 5k miles on the motor with them in and haven't had any issues, just as responsive as ever.

Yes I have heard all the hype about the FD plugs, I have been told that they will break the motor. People have said they have seen the damage, I have not seen even rub marks on anything so I would like to see pictures before I believe much. Now I will admit once I can buy the plugs locally I will be running them again but it has been a while and nothing yet.


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