Helpful Tips For Better Fuel Economy In Our Region
12-12-2004, 01:27 AM
#1
Go Texas Longhorns!
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Helpful Tips For Better Fuel Economy In Our Region
Since I’m kind of an efficiency nut, I’ve been doing some detailed studies of our 8’s fuel economy, since that is obviously one of the hot button issues with our cars. Since I think environmental conditions have a meaningful impact, I thought I’d share my thoughts on my findings in the regional section since nearly everyone here has fairly similar weather/temp/humidity conditions, or in some cases better, than Houston. Combined with Houston’s terrible traffic (I live in the heart of the Galleria), I hope I’m as good a torture test as any for gas mileage.
I should preface this with my typical driving style. All of these observations are with city cruising shifts in the 4K range with the occasional 5-6K shift and maybe a handful of redlines. I set the cruise on 70 on the hwy and roll. My car has about 7,000miles on it. I do some mild spirited driving during these tests, so I wasn’t driving like a grandma in the city.
1. Make sure you have the “M” flash, which seems to lean out our air/fuel mixture for both better economy and performance.
2. Tire Pressure – I check mine once a week, higher than the recommended 32lb doesn’t seem to help, but make sure its at 32. Not to mention your tires last longer and the care handles better (NOTE: Becareful, now that Houston is experiencing some rather dramtic temp changes from lows in the 30s-40's to highs in the 70's, your tire pressure will jump around as well. All the more reason to check it once a week)
3. Keep Moving – Ok, I know this sounds obvious, but crawling on the freeway at 20 is better than stop and go at 40, I know I’ve done a lot of both. Just think about your commute, and try to find a way to stop as little as possible.
4. A/C – Ok this is killer, I’ve done several long distance trips @70mph on cruise and managed to get 24+mpg without the A/C on. In fact, driving to San Antonio just recently, I got 25.7mpg with no A/C. My return trip with the A/C on, got me 22.7mpg. City wise this is also a big deal, in the dead of summer with normal driving, I average ~15mpg with the A/C on. Without the A/C were talking 17-18mpg.
Now that the weather for this region is cooler, we here in Houston get about 5 months of minimal to no A/C, which should help everyone across the board. A/C is a big drag on the car, I have found that if you have to use it, fire it up to cool the car off, then just switch over to the fan with the air set to reticulate.
5. Transmission Fluid Swap – Royal Purple or Redline, get it and enjoy it. Makes the car shift smoother and should make the drive train more efficient at the margins. Best single mod to date for the money, and you only have to change it every 40-60K miles depending on your driving style.
6. Alignment – Houston roads suck, and potholes suck even more. After installing my suspension, I went to NTB, paid $130 for a 3 year unlimited alignment and get it checked every 6 months unless I feel something outta wack. Not only does this extend the life of the tires, which are $$$$, it improves the handling and gas mileage.
7. Royal Purple Engine Oil – I’m going to include this b/c its possible this is helping me as well. I know that some people are not fond of synthetic as per previous debates, but I figured since they claim it can help, I should mention it.
8. K&N Filter – Ok, we have a Cold Air Intake already, the aftermarket intake kits thus far appear to be a waste of money, but this simple $50 filter helps the car breath better and is reusable. We have a good intake system, just upgrade the filter and be done with it.
I should preface this with my typical driving style. All of these observations are with city cruising shifts in the 4K range with the occasional 5-6K shift and maybe a handful of redlines. I set the cruise on 70 on the hwy and roll. My car has about 7,000miles on it. I do some mild spirited driving during these tests, so I wasn’t driving like a grandma in the city.
1. Make sure you have the “M” flash, which seems to lean out our air/fuel mixture for both better economy and performance.
2. Tire Pressure – I check mine once a week, higher than the recommended 32lb doesn’t seem to help, but make sure its at 32. Not to mention your tires last longer and the care handles better (NOTE: Becareful, now that Houston is experiencing some rather dramtic temp changes from lows in the 30s-40's to highs in the 70's, your tire pressure will jump around as well. All the more reason to check it once a week)
3. Keep Moving – Ok, I know this sounds obvious, but crawling on the freeway at 20 is better than stop and go at 40, I know I’ve done a lot of both. Just think about your commute, and try to find a way to stop as little as possible.
4. A/C – Ok this is killer, I’ve done several long distance trips @70mph on cruise and managed to get 24+mpg without the A/C on. In fact, driving to San Antonio just recently, I got 25.7mpg with no A/C. My return trip with the A/C on, got me 22.7mpg. City wise this is also a big deal, in the dead of summer with normal driving, I average ~15mpg with the A/C on. Without the A/C were talking 17-18mpg.
Now that the weather for this region is cooler, we here in Houston get about 5 months of minimal to no A/C, which should help everyone across the board. A/C is a big drag on the car, I have found that if you have to use it, fire it up to cool the car off, then just switch over to the fan with the air set to reticulate.
5. Transmission Fluid Swap – Royal Purple or Redline, get it and enjoy it. Makes the car shift smoother and should make the drive train more efficient at the margins. Best single mod to date for the money, and you only have to change it every 40-60K miles depending on your driving style.
6. Alignment – Houston roads suck, and potholes suck even more. After installing my suspension, I went to NTB, paid $130 for a 3 year unlimited alignment and get it checked every 6 months unless I feel something outta wack. Not only does this extend the life of the tires, which are $$$$, it improves the handling and gas mileage.
7. Royal Purple Engine Oil – I’m going to include this b/c its possible this is helping me as well. I know that some people are not fond of synthetic as per previous debates, but I figured since they claim it can help, I should mention it.
8. K&N Filter – Ok, we have a Cold Air Intake already, the aftermarket intake kits thus far appear to be a waste of money, but this simple $50 filter helps the car breath better and is reusable. We have a good intake system, just upgrade the filter and be done with it.
Last edited by brillo; 12-13-2004 at 12:40 PM.
12-12-2004, 08:32 PM
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I'll hold you on 1-4 brillo, since I'm forced to commute everyday to school, sometimes in the worst traffic (HWY 290). When I first started driving last year, I used to drive in a stop-and-go fashion; killed my gas mileage. Now, I keep my distance and go at my own pace, and it went up from about 15 to 18 mpg. Good observations though. Keep us posted, and hopefully we'll meet again at the next meeting. 
Eugene
Eugene
12-13-2004, 09:11 AM
#4
Registered User
I agree...
Hey folks. Houston n00b here.
I can relate to the mileage and the drive. My ride is 100 mile round to and from work (Cypress to Brenham) on 290.
I tried setting the cruise at 76 and got about 19 mpg (A/C condensor on). Cutting the speed back to 70 yielded 22 mpg (A/C condensor on). So what if I get passed by a bunch of vehicles. It's my car, my space, the speed limit is 65 and I like the looks I get (people love this car).
As far as the tires, I like 35 cold. No real reason, just had them that was on a previous vehicle. I'll try 32 cold and see what happens.
Joe Meyers is going to put the "new" M-flash in this weekend. We'll see what that does to help.
My question is, how effective is the K&N? Are we talking a percent increase or a full 1-2 mpg increase? Yeah, it's only $50, but still, $50 in my pocket is better than for something that doesn't work.
Lastly, any pro's or con's about a Mazda front end cover (bra)? My nose is taking a beating and it's either psend the money now or repaint in a year of so.
Thanks, and I am really trying to break free for a Houston meeting. Here's hoping for 2005...
Later...
I can relate to the mileage and the drive. My ride is 100 mile round to and from work (Cypress to Brenham) on 290.
I tried setting the cruise at 76 and got about 19 mpg (A/C condensor on). Cutting the speed back to 70 yielded 22 mpg (A/C condensor on). So what if I get passed by a bunch of vehicles. It's my car, my space, the speed limit is 65 and I like the looks I get (people love this car).
As far as the tires, I like 35 cold. No real reason, just had them that was on a previous vehicle. I'll try 32 cold and see what happens.
Joe Meyers is going to put the "new" M-flash in this weekend. We'll see what that does to help.
My question is, how effective is the K&N? Are we talking a percent increase or a full 1-2 mpg increase? Yeah, it's only $50, but still, $50 in my pocket is better than for something that doesn't work.
Lastly, any pro's or con's about a Mazda front end cover (bra)? My nose is taking a beating and it's either psend the money now or repaint in a year of so.
Thanks, and I am really trying to break free for a Houston meeting. Here's hoping for 2005...
Later...
12-13-2004, 10:36 AM
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Great Post!
Great post Brillo. Thanks for helpful information. It sounds like it's not worth spending $500 on an air intake. Are you suggesting changing the transmission fluid in the 6 speed RX-8's as well? If so what type of fluid does the car take? Thanks again for the great post.
12-13-2004, 12:38 PM
#6
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Glad to see people are finding the info useful. Davinci, yes I was refering to both, I have the MTX 6spd and I can't say enough about how much I love the Royal Purple tranny fluid. If your not confortable doing it yourself, just Call MazMax here in Houston and Brian will help you out.
As far as the intake system goes, our intake is one of the best designed ones I've seen. Its already cold air, has a good flow design (other than the filter) and isn't loud. I'm sure Racing Beats intake system may add some HP (3-5) and a better sound but thats it. Since so many people are having idle/engine issues with the various pipe/cone intakes (ie K&N, SR Motorsports etc.) I would just get a high flow filter instead.
I've used either a CAI or filter on all my cars, and for most of them, I would say it netted an extra 1mpg over the life. The jury is still out on the 8, given that mazda invested so much engineering to the 8 thats its hard to improve on, I'm almost surpised that they didn't create a better HF filter, if for no other reason than its one more way to squeeze every drop of gas out of the engine.
Really and truely, the biggest gains are going to be using your A/C and your driving style / environment. I even leave earlier for work now, only 10 minutes or so, but it makes my commute so much more pleasent. I then don't want to go postal at the office, and save gas at the same time. That said, I think the little axtras do add up and are both good for the cr in terms of reliability and economy.
As far as the intake system goes, our intake is one of the best designed ones I've seen. Its already cold air, has a good flow design (other than the filter) and isn't loud. I'm sure Racing Beats intake system may add some HP (3-5) and a better sound but thats it. Since so many people are having idle/engine issues with the various pipe/cone intakes (ie K&N, SR Motorsports etc.) I would just get a high flow filter instead.
I've used either a CAI or filter on all my cars, and for most of them, I would say it netted an extra 1mpg over the life. The jury is still out on the 8, given that mazda invested so much engineering to the 8 thats its hard to improve on, I'm almost surpised that they didn't create a better HF filter, if for no other reason than its one more way to squeeze every drop of gas out of the engine.
Really and truely, the biggest gains are going to be using your A/C and your driving style / environment. I even leave earlier for work now, only 10 minutes or so, but it makes my commute so much more pleasent. I then don't want to go postal at the office, and save gas at the same time. That said, I think the little axtras do add up and are both good for the cr in terms of reliability and economy.
12-31-2004, 01:34 AM
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All good tips and over the last 6 months, I have tried them all. I get the worst mileage that I have seen anyone mention. I have been to Joe Myers 4 times on it in the last 6 months . At first they said it was too low. AT the time it was getting 13-14. Recently they said it is normal now that it is down to 9-10 or more precisely 8.7-10.1.
BTW, the 10.1 was using the 8500 rmp beep as a time to shift indicator and running WOT as much as possible. the 8.7 was using every tip your offered and a lot of coasting where possible to just keep it moving. No AC with either.
They are supposed to arrange a meeting with the District Customer Service Manager sometime.
Funny thing is 2 weeks ago, I got a CEL and took it in. They said it was the gas cap and replaced the assembly. Now the mileage hasn't changed, but it has a more throaty sound coming from the intake and the butt dyno doesn't think it feels as underpowered as it was.
I better go check to see if they took the air filter out and forgot to put it back in. Arrrrgh.
BTW, the 10.1 was using the 8500 rmp beep as a time to shift indicator and running WOT as much as possible. the 8.7 was using every tip your offered and a lot of coasting where possible to just keep it moving. No AC with either.
They are supposed to arrange a meeting with the District Customer Service Manager sometime.
Funny thing is 2 weeks ago, I got a CEL and took it in. They said it was the gas cap and replaced the assembly. Now the mileage hasn't changed, but it has a more throaty sound coming from the intake and the butt dyno doesn't think it feels as underpowered as it was.
I better go check to see if they took the air filter out and forgot to put it back in. Arrrrgh.
01-04-2005, 08:44 PM
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Originally Posted by RX4+30Years=RX8
All good tips and over the last 6 months, I have tried them all. I get the worst mileage that I have seen anyone mention. I have been to Joe Myers 4 times on it in the last 6 months . At first they said it was too low. AT the time it was getting 13-14. Recently they said it is normal now that it is down to 9-10 or more precisely 8.7-10.1.
BTW, the 10.1 was using the 8500 rmp beep as a time to shift indicator and running WOT as much as possible. the 8.7 was using every tip your offered and a lot of coasting where possible to just keep it moving. No AC with either.
They are supposed to arrange a meeting with the District Customer Service Manager sometime.
Funny thing is 2 weeks ago, I got a CEL and took it in. They said it was the gas cap and replaced the assembly. Now the mileage hasn't changed, but it has a more throaty sound coming from the intake and the butt dyno doesn't think it feels as underpowered as it was.
I better go check to see if they took the air filter out and forgot to put it back in. Arrrrgh.
BTW, the 10.1 was using the 8500 rmp beep as a time to shift indicator and running WOT as much as possible. the 8.7 was using every tip your offered and a lot of coasting where possible to just keep it moving. No AC with either.
They are supposed to arrange a meeting with the District Customer Service Manager sometime.
Funny thing is 2 weeks ago, I got a CEL and took it in. They said it was the gas cap and replaced the assembly. Now the mileage hasn't changed, but it has a more throaty sound coming from the intake and the butt dyno doesn't think it feels as underpowered as it was.
I better go check to see if they took the air filter out and forgot to put it back in. Arrrrgh.
Food for thought!!
Good luck!!
- Irish
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