ptiemann

Yes, I agree on that. But before we started doing this thread, we couldn't know, or? So now we're smarter.

And those 3 or 4 guys who constantly are below 15 mpg, they have now a list with lots of VINs, they can go to their Mazda dealer and use this list as leverage to get a new motor or whatever.

-Peter

Racer X-8

Here's the bell curve...

LambertRX8

vin **********106998

averaging 18.24 80% highway driving cruising at 75mph for 100miles.

Gets worse in the city.

ptiemann

Somewhere I read yesterday in a thread on drag and CD coefficient, that at a speed of 100 mph the RX-8 will yield only 10 mpg - does that sound anywhere realistic? I drive 80 all the time with 90-100 when the freeway allows it - and I still come out with 20 or 21.

norton

Racer X-8: What's your background? You and I both appear to be "Numbers Moles". My background is economics. By the way, what's the Buckingham Pi theory?

RX-GR8

14.8-17.8 90% city.

Racer X-8

Hey there Norton,

I'm a mechanical design engineer. Lotsa numbers everywhere!

Buckingham Pi Theorem is a method that eliminates un-neccessary variables in analyzing unknowns. Pretty wild abstract stuff! I've used it & it works though. Not sure I know how though...craziness... :D

I just entered "Buckingham Pi Theorem" in the address and the search came up with several sites to check out. Bon apetite!

Oh yeah, it makes for a great CB handle too. "Buckingham Pi, knockin on your back door, good buddy!"

madhaus

100885

worst 13, usually 14 or 15 around town with a very heavy foot

best was 24, 65 MPH on cruise control for 200 miles.

silver8

Perhaps delivery date might provide more correlation to mileage than build date as it may reflect changes in ECU programming that I believe take place at the port. As tight-lipped as Mazda is being, they may have changed the ECU maps they load. Just a thought?

Also, while it would be interesting to gather about 15 points of data for the spreadsheet, it may not be feasible. But if columns were added for different things, it would be easier to search for correlations. One column I would like to see is the average distance per trip...as I think the 8 gets it's worst mileage when it's cold. If I am right, than this metric would be every bit as important as the city/highway mix.

BTW, nice excel work there Racer!

Racer X-8

Thanks!

I agree with you on average distance per trip, cold starts & city/highway mix. Like every other car known, these factors must affect fuel efficiency. What I'm trying to say here is, lets not re-invent the known factors that affect fuel efficiency. That's good stuff to know, then apply in a loose kind of way to justify your mileage in a relative way with the average combined mileage.

Like, take me for instance. My avg. mpg is 19.7 which is better than the 18.3 combined avg. Well, of the 2000+ total miles on my car, I took a 1500 mile trip to Florida. So, more than half of my car's history is cruzin' around on highway. I don't doubt that my real average mpg will settle down a good bit, and 18.3 sounds just about right. My avg before the trip was in the 17's & climbing, after the break-in period / after my engine got over it's newness & loosened up a tad. The trip avg was about 20.5

I like your thinking on delivery date at the port, that it may reflect changes in ECU programming which affect fuel efficiency. That also brings to me the engine build date, the engine builder & the recieving port.

We can forget about the engine builder, right? We'll never know his/her name.

Engine build date? Is that anywhere? I think there was something about that date...darn, I'm already forgetting...

We used to know a lot about the ships coming into port. I know my car left Port Jacksonville right at the end of July. Do the newer buyers have a clue about theirs? I don't think so.

That's all I can say at this time...

Norton might hit onto something with what he's doing in his thread...

ptiemann

you can find out the build date by calling Mazda customer service and providing them the VIN.

Supposedly it can also be done on the web site where you can register with your VIN, but that web site and my browser didn't get along too well.

I haven't called Mazda yet, I always assumed that they give the number incremental.

-Peter

lamigre

101021
13 city
25.5 highway.

canzoomer

101877
Mostly highway
15.82mpg combined

Racer X-8

Canzoomer, wuddup! I'm gonna "pick on you", cuz you gave me what I need for the graph. You left out info for the spreadsheet though. If I wanted to knock out a graph to compare avg. mpg .vs. transmission type for example, there would be no data point for you, cuz I don't know what transmission you have. You probably stated it in another thread, but I'm not gonna go hunting for it.

Others (and I'm not talking about anybody, I'm just talkin' 'bout what I'm talkin' 'bout) have left me clueless about their combined average mpg. I can't use them. I've guessed some people's avg. mpg before, but I'm not gonna anymore.

The baseline info. that I need is only two things, and I need them both:

1) VIN
2) AVERAGE MPG

The other info is icing on the cake, but I need the first two bits of info. to get you on the spreadsheet.

And, as Elvis would say, "Thangk you verrrry muuuch".

canzoomer

Fair comment.
VIN: 101877 - one of the first batch over. #1877

Average mpg in "normal use ( I have been doing performance tunig, so I will leave those tankfuls OUT of the equation, as they are horribly skewed. You don't get great mileage on a dyno!

15.819mpg (US Gallon) or 14.869 liters per 100km

Racer X-8

Canzoomer, what I wrote was that you were one of those that did give me both things that I need. You were OK with your first post & I already had you added to the spreadsheet before I even posted this morning. This last one had some of 9that extra "icing on the cake" that I was mentioning, so, good. (I still don't know your total miles, date when you got your car, transmission (MT or AT) & if you have the aero package.)

And let me make this perfectly clear...
I'm just using canzoomer as an example I used canzoomer cuz he already gave me what I needed, so, he done good & so he won't get pissed off at me...
I want everyone to give me at least the VIN & avg. mpg, like canzoomer did. Also, the other info on the spreadsheet is wanted, but not neccessary.

I was wondering how your persuit of extra horsies was going. Glad you're trying! Do you have a thread going on that topic? I would like to know how you're doing with it. I'm sure everyone else would like to know too...

canzoomer

Probably best to read this thread from page 8 on:
https://www.rx8club.com/showthread.p...5&pagenumber=8

Quest is done, now building parts and doing last beta testing with a coupleof other RX-8 owners and their cars.

Working with a sample of only one car is not enough, so wanted to do this last step, before we ship units to the public.

Fuel economy gains will ostly seen by drivers with an aggressive foot.
The biggest part of economy gain is to be had over 6,000rpm, so that is where we focused. Below that the stock mixture is actually pretty lean, so not so much there.

In other words, if you are one of the people like me who like to put the hammer down, you will gain about 2 to 3mpg.
If you shift by 3500 ( and already get better than 18mpg) you will gain little.

norton

The baseline info. that I need is only two things, and I need them both:

1) VIN
2) AVERAGE MPG

Racer X-8: I'll provide the data you're looking for above in the results of the Regression Analysis. I have nearly 30 obs. so far. I'm hoping to get the results by this evening.

Racer X-8

Thanks norton. I dunno why I didn't think of that...

CANZOOMER: OH MY GOD!!!!!!!

I don't know HOW I've been missing out on all that fun you've gotten yourself wrapped up into! That thread is totally new to me & I will take all the time required to catch up on all 1000 pages of it (OK, exagerating a little there). I've read enough though, to figure that you've been doing a terrific job, dude! I am thrilled!!!

canzoomer

Heh...heh...
It's been quite a ride so far.

RX8driver

I got a call from Mazda today and they wanted to know if I had a 6 speed or automatic! I have a 6 speed, and they said they were only wanting to talk with customers with an automatic transmission; apparently she said they had enough comments from people with 6 speed manuals. Perhaps this is just routine, but it's curious... I don't believe they ever called me for my other Mazda.
Any thoughts?

Racer X-8

Hmmmm.

Maybe they only saw the info you gave me in your 10-22 post & didn't know that you PM'd me more info, including the fact that you had a 6 speed & wanted to verify that the info in my posted spreadsheet was accurate. Sneeky devils...:D

Jump120MPH

100082..........17-22

Racer X-8

Wow! Tha't's the lowest VIN so far, I think.

Is your average 19.5?

Also would be nice to know the other spreadsheet entries for you. See page 7 for a look at the spreadsheeet...

Jump120MPH

Yeah its about 17 city 21 highway