23mpg
 

this last tank was 23mpg 218.8 miles and 9.493 gallons, consisted of 1/3 my 3 mile commute to work stop and go, 1/3 weeked cruising, and 1/3 tuning and boosting the shit out it. overall i'm pretty happy with that considering stock was rated 21city 27 highway on my 93.

But i'm wondering if i can do better. is anyone beating that without highway driving? if so what are you're afr's tuned at idle, normal driving, and cruise? or any other tips to improve any in ms?

on my old turbo probe, i was getting 35+ mpg highway with megasquirt at a 14.7 afr

Boy, I wish I could average 23 mpg! :D

On the highway with the top up, I get just about 30 MPG. Despite being small and lightweight, the Miata is not very aerodynamically efficient.

In town, 19-20 is more typical. Of course, I'm not terribly gentle on the throttle.

man ive been babying my car around lately ... hardly even hit boost anymore with gas prices. Anyway ive tried to tune pretty much anything under 70kpa to around 16:1ish and have aggressive EGO correction up to that point to keep it running lean (15% max change, 32cycles, stepsize 1, 1500rpm)

Anyway, ive gotten like 20mpg in the past but recently went more lean with my fueling and i think its going to get a few points higher this time.

Around town, I do about 18 or so. If I stick to 70-75mph, I can do around 27mpg. If I cruise at 80+, I end up at 24-25mpg.

do you have a 4.1 final gear? did you factor in this loss?

I have to add 10% to my tripometer to get my correct mpg. with that said I achieved 22.5mpg city only.

Since I've switched to COP's and bumped up to the "hybrid" spark map, the lowest tank I've had is 24mpg... and that included a lot of boosted tune runs. I'm pretty sure on the freeway at 70mph w/about 15-18vaccum, I get about 30mpg. But I also see 14psi at every stoplight, every onramp, and every Honda.

I'm usually around 26 mpg, I drive like most of you, cruise like normal, but see 14 psi when I'm feeling saucy.

Grape vine to 152 on hwy5 (CA, reasonably flat running for ~200 miles or so) with the CC set at 75 and AC on I was getting about 23mpq (a couple of minor deviations, when a BMW started tailgating for some reason and needed to be ditched, twice; but it was mostly just on cruise control).

I get 26 on an average tank, but over 35mpg on the motorway and I run 11psi of boost.

ive always noticed that people in california get worse mileage than the rest of the nation, couple of points or so.

I wonder...Did the Miata have a CA and a US version? I know a lot of newer cars have slightly different parts(mostly smog related) depending on whether or not htey were desined to be CA cars which might explain some slight MPG differences

I average 29mpg, but I drive sloooow....

Same here...I get about 27 city. I never drive on the highway since it's summer and im a lazy ass.

normal me driving i pull bout 25 me driving fast i pull bout 16, how and where you drive is important. Hardtop helps me to. Ive had 30-33 pre ms on rrfpr etc. no word on top of ms though.

For some years yes, for some years no. For example, '90-'92 were 50 state cars, but in '93 the CA car for sequential injection which the 49 state car didn't get until the 1.8 engine a year later.

It's fairly irrelevant however, as we tend to remove all the bits that differentiate the cars when we go MS. ;)

I suspect that the difference has to do with our fuel having a lower energy density.

I got 25 last tank, due to the top being down and nearly all city driving. With the soft top up, I'll get nearly 30 and over 30 with the hard top. This includes WOT from 1st to 4th as often as possible, as well as plenty of pulls from 4 to 6-6.5k in 5th--Just so I can hear it go "PSHHHHEWWW". :fawk:

19.2:1 FTMFW

What injectors are you using?

I can't seem to get better than 24mpg on my stock 1.6.

i'm using rx7 550cc pnp inejectors that flowed out at 620cc

No shit! Well done! :bigtu:

Mine are also 550cc. I guess I have a lot of work ahead of me! ;)

This reminds me that I've got to do some "cruise" tuning. I think I'm sitting pretty rich at around 15:1 in cruise most of the time. That being said, I just filled up last night and got 26mpg... including A LOT OF TIME WITH THE EBC ON! I think I can manage a few more mpg's with some laptop time. There's definitely 30+mpg in it somewhere. If I could keep my finger off the EBC switch, I'm sure 28mpg would be the norm.

You'd probably be better off with smaller injectors. But what's done is done. Tune it leaner.

I still don't understand why you guys like to cruise around at stoich? Lean that bitch up. Just leave it fat for when you stand on the loud pedal. I get fantastic economy, and very few of you fuckers make more power than me*

*built motors need not apply

I've leaned out my AFM out to 15.1 idle and cruise. Normal mixed driving (highway/surface/sprited) I get a tad over 24 mpg. I've never driven an entire tank on surface streets and I don't plan on doing that. On the highway, I've gotten as high as 32 mpg driving conservatively.

Currently, I'm driving extremely conservatively to see just how high my mpg can go with mixed driving.

Anyone monitoring their egt while leaning their cruise?

Yes I have a pyrometer on my a pillar

Yes, temp is up slightly.

add a little bit of timing

I've been getting 17 for as long as I can remember. I thought it was cold start settings since most of my driving is 7 miles to work on back roads, and 7 back. With the miata club, I get 30-32.

I used to cruise very lean, but it didn't really help, richening it up got me better response, so I try to stay in the 15-15.5 range. I keep wanting to tune it for economy, but haven't yet. I need to have something that spits out fuel usage per revolution as a loggable variable into the MS code, then I could get economy out of it pretty easy.

are you being serious with 19.2:1?

also you guys getting really good mileage show me your afr target tables and spark tables please:)

Yeah - I was running 18-20 AFR's for a while. But you're less effecient since you need more throttle to get the same power. Or, you can be. Lean burn is fine, but overdo it and you should hurt your mileage. Also, spending at least 5 minutes a day out of boost helps. So I hear, I wouldn't be knowing.

on ms i run bout 16-1 and have a decently agrressive overrun in cruise that puts me to 20-1 or so.

Yeah

Abe--it's more complicated than that. Wider throttle angles mean lower pumping losses. And remember it doesn't take much power to maintain cruise. So super lean cruise is great as long as you have your accel enrich set to keep you fat when you accelerate.

Proof is in the pudding. My car is fast, responsive, and gets wonderful economy.

Ok, I will give you that. I messed with lean cruise before I got even close on my accel enrich settings. I will revisit this.

Got a good source for EGT probes? I got one I thought would be good, it lasted like 3 months.

Look it up, the CA version has completely different exhaust system so they can be overly cautious with their emissions.

The cali versions are only different in a few years. And it's not just cali. NY also gets the same cars, and I think one maybe two other states. DEfinately in 99-00. I think in '01 everyone gets the same again.

My car is from TX. Still smells of queer.

:giggle:

-wrong forum-

I could argue against that considering that they're discussing how to tune cruise for best effenciency.

WTF are you?

<--- Yeah that's right SUPER mod bitch

I say let them play through

Ben, so how much timing are you running in your cruise map (3k-4kish and 20-60kpa) Ive got mine tuned to 16:1 and roughly 35 - 40* of timing there, still not getting fantastic economy though ... last fillup was 18mpg but with 3.9 gears and unknown speed sensor since the tranny was replaced with a 97 trannie at some point so 5 or 10% more depending on that, and i hardly even boost nowadays because premium is $4.78 here :( fuck that.

So Ben, what do YOU average fuel economy?

Reading is fundamental
https://www.miataturbo.net/forum/sho...1&postcount=17

Last tank was 28--top down.

But the 30 was from city driving too? That's what I was getting at.

Hmm, so you're running an unknown speedo sensor and you think your speedo or odo are going to in any way be accurate?

Stop and go rush hour highway and around town. No real cruising.

Alright, two things Ben, 1) is there a thread somewhere with all of your current setup specifics listed? 2) How long did you spend tuning to perfect your fuel economy?

No--vB garage is quasi current

A couple of weeks, actually like 1.5 wks probably for the street tune that's in it with the HR firmware. Spark map is based off my dyno tuned standard code spark map, just advanced some more in cruise. I'd like to dyno tune this set up, but it doesn't make sense to spend the money right now.