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I will wait to make the vacuum advance adjustment [+2 turns clockwise] until this tank is completed. I want to see if the in-town mileage average has been affected by the changes made over the weekend.
I want to point out that with the addition of the factory chin spoiler [see list above with "*"], the next tank representing in-town mileage improved. Only one data point is not enough, but when you add that to the fact that on this trip [with chin spoiler] the truck achieved two 23+ mpg tanks, which in 6+ years has never achieved greater than 22 mpg. It looks like the spoiler actually helps with gas mileage.
To be continued...
It has been 9 days and 217.4 miles since the truck was filled up, at the completion of the trip to OK. This tank represents the normal driving done by me and can be compared to the previous data with the only difference being that the weather has turned considerably cooler at night. The onset of cool weather can be expected to decrease mileage according to the records.
9/23/14 217.4 miles 11.673 gal. 18.62 mpg town/mild
I had hoped to see an increase in mileage since the adjustments made at the OK GTG, but just like with the previously discussed highway mileage, it looks to be about the same as before, but the sometimes dragging while starting and the pinging while under load have been eliminated.
The next step is to adjust the vacuum canister two more turns [clockwise] which will cause the vacuum advance to come in sooner.
David - That's still very good mileage. Not only is it nothing to be ashamed of, I suspect it beats all other 80-86 trucks represented here, and most of them quite handily. So, it is hard to improve on something that is at the top of the curve. However, the adjustment on the vacuum advance may do that, although perhaps so marginally that it will be hard to see in the numbers.
Speaking of sealing in the numbers, how far back do your records go? If you have several years of them then we could look at them on a Jan through Dec chart and potentially see the later years, representing the incremental improvements, run just a bit higher than the previous year. If you aren't a spreadsheet guru then I'll be happy to input the data and create the charts. We have the data earlier in this thread, so if you want to post the data prior to the 7/23 point I can work from that.
Hmmm? Let's see, I have owned the truck for 6+ years and the 1st tank was about 8 mpg and the second was about 11, if memory serves me well. I use a tank every 8-9 days. Sure you are up to the task?
By the way, the 2 turn clockwise vacuum canister adjustment has been accomplished. I am hoping for slight ping under light throttle.
Hmmm? Let's see, I have owned the truck for 6+ years and the 1st tank was about 8 mpg and the second was about 11, if memory serves me well. I use a tank every 8-9 days. Sure you are up to the task?
By the way, the 2 turn clockwise vacuum canister adjustment has been accomplished. I am hoping for slight ping under light throttle.
Hmmm, you have records for ~42 tanks/year and 6+ years? That means 250 tanks? I can do that, but not overnight. In fact, this is the season in which to do it - the end of the regular baseball season with the playoffs and the series coming. Lots of quite, slow evenings with plenty of time to type.
Dunno how best to get them to me though, as if you type them then you do all the work. Hey, works for me! If we do this correctly then all I have to do is to cut/paste them into a spreadsheet and set up the charts. You up for that, or some of that?
As for the vacuum advance, here's hoping you'll soon have some ping. But, we didn't really look at the mechanism to see if a V8 unit would swap. If it did then we might get more advance rather than just earlier advance. Or, maybe there's a stop that we can mod to get more advance. Can you take a pic with the cap off, and maybe the rotor off, of the innards of that dizzy?
I have the data in from 7/13/13 to today. Well, all but the notes. And, here's what I have to date:
The X axis is a mess, but shows the odometer readings. Unfortunately I can't figure out in Open Office how to do what I could in Excel, like only including every other or every 10th odometer reading. Anyway, you can see the trend, which is supposed to be represented by the solid yellow line, called Exponential (MPG). And the Running AVG is an average of each pair of adjacent data points to smooth out the issues of getting a bit more in one time than another. (Note to self - I would have expected the average line to start one data point later and carry on to the same ending point. Instead, it starts with the other line and ends one data point early. )
What is pretty obvious is when you re-adjusted the timing, which was at 170, 718 miles on 2/28/13. At that point things picked up nicely, but we see the trend that you've noticed of the MPG improving as the temperature comes up. And, if you didn't know that trend was in there you'd expect the MPG to just continue right on up, but we know the weather influence is about to dwindle.
However, since you've twisted the wick two more turns on the vacuum advance we might see some improvement, although the cooling temps may negate that. So, how is the truck driving with the earlier advance? Can you tell any difference?
First, to answer Gary's question regarding performance after adjusting the vacuum canister 2 more revolutions [clockwise]... I think the engine is closer to having a very slight ping when under light load. I have good hearing and believe there is a slightly different sound coming from the engine when under light load, but I would not yet classify it as pinging. I will finish out the current tank under the present conditions and then give it two more turns. If pinging comes on too soon or too hard, I will then turn 1 turn CCW. The engine still starts easily and does not ping under full throttle.
To answer Jim's comment... yes, you are correct. However, since the records are for 6+ years, the reduction in mileage during the winter months has established a pattern, which at least can be compared to similar time frames of the prior years.
What I am thankful for is that the truck no longer returns mileage like the first two tanks which were 9 and 11 mpg with horrible performance. Again, thanks to all of you who have taken an interest in this project and have contributed so much!!!
Would some of you please "rep" Gary Lewis? I cannot, and he has worked very hard in assisting with this project and it was his idea to record the data of an F150 with decent gas mileage so that others can duplicate "the total package" if so desired.
Jim - Yes, winter blend is coming, but as Davis said we should see a pattern and be able to pick out the improvements over the pattern. My hope is to break the data up into annual curves that let us compare the changes year-over-year as well as the impact the winter blend, stiffer lubes, and choke engagement give.
David - At some point I'd like to consider mods to either the vacuum advance or the dizzy to get more total vacuum advance. But you do have the process down, so it will be interesting to see what the next twist of the wrench gives.
Ok, time for a philosophical/technical question. IOW, HELP! What I think would be good is to show the MPG on an annual basis, maybe Jan - Dec, or maybe Octoberish to Septemberish to put the winter-blend gas and the cold all together. If you agree, then comment on the start and end dates. If you disagree please 'splain why.
But, the other question is how to do that when, as methodical as David is, there are differing numbers of fillups in each year. So, a different # of data points and differing lengths of curves, therefore hard to compare. It seems like it would be better to have a constant # of data points, which means I need to interpolate the data. One approach to that would be to average it by month, so 12 data points per year. Is that reasonable? If not, what is?
Or, is it better to have one really, really long set of curves with everything in by date or odometer?
Here's what I'm talking about. This is the data I have in to this point: Oct 2012 to Sept 2014. I've averaged each month's data so that there are (will be) 12 data points for each year.
This points out very graphically the much better MPG that the truck is getting in 2014 over 2013. However, you cannot see where David adjusted the timing on 2/28/13 like you easily can in the previous chart. And, it looks like something is amiss in 2012 as it ended the year with much better MPG than 2013 did, but apparently David took the truck on highway outings in Nov & Dec of 2012 as there are some legit 20 MPG readings in the log. Also, you can see that Sept of 2014, to date, was significantly helped by the road trip to/from the OK GTG. (I wish we could say it was because of the tuning we did. )
So, while this layout/format allows you to do a year-to-year comparison, the averaging hides road trips and tuning changes. What are your thoughts, folks?
09-17-2014, 08:44 PM
If it did then we might get more advance rather than just earlier advance. Or, maybe there's a stop that we can mod to get more advance. Can you take a pic with the cap off, and maybe the rotor off, of the innards of that dizzy?
)
Again, thanks to all of you who have taken an interest in this project and have contributed so much!!!
