MPG- give me some input please
#1
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Hey,
I would like to know if my fuel consumption is normal.
Lately I run on low boost 7-8psi in order to see if that will help my mpg.
It almost made no change, I run 12-17mpg (5-7km/liter)
Normal ?
This is my AFR auto generated table:
![](https://www.miataturbo.net/attachments/megasquirt-18/113903d1400844469-mpg-give-me-some-input-please-capture.png)
What do you think ?
I would like to know if my fuel consumption is normal.
Lately I run on low boost 7-8psi in order to see if that will help my mpg.
It almost made no change, I run 12-17mpg (5-7km/liter)
Normal ?
This is my AFR auto generated table:
![](https://www.miataturbo.net/attachments/megasquirt-18/113903d1400844469-mpg-give-me-some-input-please-capture.png)
What do you think ?
![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
Last edited by elior77; 05-23-2014 at 12:09 PM.
#3
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first off, you mean mpg right? cause even a semi truck doesn't use 17 gallons per mile
second, your target afr table means nothing to us, you'll need to post logs or tell us what its actually achieving.
third, what fuel are you using.
lastly, if you're not getting the same mileage driving it normal as you did when it was unmodified, then you either have a problem or your tune sucks. at worst it should be within 10% difference. that's assuming you're not constantly WOT and in boost
Please stop posting lazy uninformative threads, or we'll stop helping you. I realize you're foreign, so there's a language barrier, but you'll still have to try harder and provide more info.
second, your target afr table means nothing to us, you'll need to post logs or tell us what its actually achieving.
third, what fuel are you using.
lastly, if you're not getting the same mileage driving it normal as you did when it was unmodified, then you either have a problem or your tune sucks. at worst it should be within 10% difference. that's assuming you're not constantly WOT and in boost
Please stop posting lazy uninformative threads, or we'll stop helping you. I realize you're foreign, so there's a language barrier, but you'll still have to try harder and provide more info.
#5
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MPG fixed.
I will post logs asap, but this table was used by the autotune so it represent quite good the actual AFR - I see my AFR live when I drive and it is the same as the table.
I use 95 (RON?) fuel.
I use a small turbo TD04-13C when I'm at 100-120kph I'm in boost (or very close to) so I can not compere it to the unmodified MPG.
When I disconnect the actuator I get close to normal MPG.
I'm sorry to understand that you think this is a lazy uninformative post, I disagree.
If some info is missing I would be happy to give it.
This is my first turbo project, I have no previous background in turbo charging or mechanics (I'm an IT guy) I do my best...
![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
logs asap.
I will post logs asap, but this table was used by the autotune so it represent quite good the actual AFR - I see my AFR live when I drive and it is the same as the table.
I use 95 (RON?) fuel.
I use a small turbo TD04-13C when I'm at 100-120kph I'm in boost (or very close to) so I can not compere it to the unmodified MPG.
When I disconnect the actuator I get close to normal MPG.
I'm sorry to understand that you think this is a lazy uninformative post, I disagree.
If some info is missing I would be happy to give it.
This is my first turbo project, I have no previous background in turbo charging or mechanics (I'm an IT guy) I do my best...
![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
logs asap.
#6
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If disconnecting the wg nets close to OEM gas mileage, then your tune might not be that bad actually. Looks like you're just dipping into boost WAY often with that tiny turbo. Also post your timing map to make sure you're not retarded too much and giving up efficiency.
I meant no disrespect with my "lazy" comment, just frustrating because I'm genuinely trying to help you out here.
I meant no disrespect with my "lazy" comment, just frustrating because I'm genuinely trying to help you out here.
#10
Cpt. Slow
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iTrader: (25)
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,360
Total Cats: 1,184
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I beat the crap out of mine and usually rev it in the driveway until it's warm. I still get 19mpg regularly. This is with cruise cells tuned, as others have said, to 15.5-16 afrs.
Here's what you do:
Go out for a drive on the freeway. Get in the slow lane and go 50mph. Put the car in 5th, or 6th if you've got it. Drive for 10 miles, paying attention to your RPM and map readings, remember them. Then go to your fastest cruising speed. In Oregon we don't have speed limits over 65, so I'd probably do this at 70mph, but your results may vary. Again, drive 10 miles at this speed, paying close attention to your rpm in top gear and map reading when CRUISING (aka: not the readings when you're letting off if you accidentally go too fast, or boosting back up).
Find the 50mph numbers on your afr target table, and draw a line straight up at the rpm, and horizontally right at the map. With the 70mph (or whatever) numbers, draw a line straight down at the rpm and horizontally left at the map.
Make all cells that fall in the box created by these lines equal to 15.5-16.0. Tune for these. If you have an hesitation or you're worried about the transition into the box, or out of the box (and/or if you have a giant MSII or better target table), you can reduce the boarder to a smaller number.
Come back with results.
P.S. Your signature is a lot better than most newbs, but make sure to ad your car's year and engine type. 17mpg with a 1.6t is much worse than a 17mpg 1.9t.
Here's what you do:
Go out for a drive on the freeway. Get in the slow lane and go 50mph. Put the car in 5th, or 6th if you've got it. Drive for 10 miles, paying attention to your RPM and map readings, remember them. Then go to your fastest cruising speed. In Oregon we don't have speed limits over 65, so I'd probably do this at 70mph, but your results may vary. Again, drive 10 miles at this speed, paying close attention to your rpm in top gear and map reading when CRUISING (aka: not the readings when you're letting off if you accidentally go too fast, or boosting back up).
Find the 50mph numbers on your afr target table, and draw a line straight up at the rpm, and horizontally right at the map. With the 70mph (or whatever) numbers, draw a line straight down at the rpm and horizontally left at the map.
Make all cells that fall in the box created by these lines equal to 15.5-16.0. Tune for these. If you have an hesitation or you're worried about the transition into the box, or out of the box (and/or if you have a giant MSII or better target table), you can reduce the boarder to a smaller number.
Come back with results.
P.S. Your signature is a lot better than most newbs, but make sure to ad your car's year and engine type. 17mpg with a 1.6t is much worse than a 17mpg 1.9t.
#13
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Way too rich. As said a target afr map means nothing however i'm assuming your real map is fairly close. That said...
1600-3800 up to 64kpa tune for 15.2. Your location is unknown however in the winter i go up to 15.5
Between 1600-3800 change 78kpa to 14.3 , 92kpa to 13.5
Also a small turbo wont make it so you're always it boost. Doesnt work that way. That depends on your throttle / rpms. Yes it spools faster than a large turbo however if u find ur self at 120kpa all the time in low rpm then you need to ease on the throttle and keep it in a higher rpm. An engine at 3-4k rpm at 70kpa will give u a better mpg than lugging it at 120kpa at 1500 rpm on every green.
1600-3800 up to 64kpa tune for 15.2. Your location is unknown however in the winter i go up to 15.5
Between 1600-3800 change 78kpa to 14.3 , 92kpa to 13.5
Also a small turbo wont make it so you're always it boost. Doesnt work that way. That depends on your throttle / rpms. Yes it spools faster than a large turbo however if u find ur self at 120kpa all the time in low rpm then you need to ease on the throttle and keep it in a higher rpm. An engine at 3-4k rpm at 70kpa will give u a better mpg than lugging it at 120kpa at 1500 rpm on every green.
#15
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Its probably worth a shot, but honestly .3-.5 of a point of afr wont' make much difference, especially in cells that get swept through real quick and usually are bouncing around to find the target.
Your normal hwy cruising should be out of boost, and it should be in the 30-40* range, and it should be in the 14.7-15.5 range. Your idle should be in the 14.5-15.0 or so, and your startup/wue should not be pig rich.
just some general pointers
Your normal hwy cruising should be out of boost, and it should be in the 30-40* range, and it should be in the 14.7-15.5 range. Your idle should be in the 14.5-15.0 or so, and your startup/wue should not be pig rich.
just some general pointers
#17
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Its probably worth a shot, but honestly .3-.5 of a point of afr wont' make much difference, especially in cells that get swept through real quick and usually are bouncing around to find the target.
Your normal hwy cruising should be out of boost, and it should be in the 30-40* range, and it should be in the 14.7-15.5 range. Your idle should be in the 14.5-15.0 or so, and your startup/wue should not be pig rich.
just some general pointers
Your normal hwy cruising should be out of boost, and it should be in the 30-40* range, and it should be in the 14.7-15.5 range. Your idle should be in the 14.5-15.0 or so, and your startup/wue should not be pig rich.
just some general pointers