Help me see 55 mpg!

[Loren]

Originally Posted by drummerboy2004

Hope this wasn't common sense...

Well, it's common sense to an experienced hypermiler. ;)

Tomorrow's the big day. Bought a roll of self-adhesive aerodynamic improver (clear packing tape) yesterday. I'll stick some of that on the car today and air up the tires. Should be good to go.

[JnC]

Originally Posted by Loren

Bought a roll of self-adhesive aerodynamic improver (clear packing tape) yesterday. I'll stick some of that on the car today ...

I'd be scared of packing tape adhesive pulling off the paint when you remove it. Would suggest masking tape instead.

Best of luck!

[metalshark]

First go get-ya some of them Imperial gallons. The canucks have an edge there....but seriously my last trip with Amsoil 5w-20 got 39.3 MPG with cruise control set at 50% 65 MPH and 50% 75 MPH. In town before the switch to light oil my best commuting was 43 MPG for three tanks straight. I still have to "have discipline" to test for mileage after the change.

[Loren]

My groove. I wasn't on it.

Worse yet, my ScanGauge was lying to me. Was in a rush this morning and didn't check MPG when I filled up or I might have caught that it was off and reset it. So, I wasn't trying overly hard today (just wasn't in the mood), just did my usual DFCO coasting and gentle acceleration, similar to what I did to net 49.9 mpg before, but with about 10psi more air pressure in the tires, lower grille and foglight holes taped, right-side mirror folded and antenna removed. I did a little bit of FAS, and I did kill the engine at stop lights... figured that would have been good for a little, but it just wasn't happening.

The ScanGauge was telling me that I was getting close to 56 mpg. It peaked at 56.2 at one point, but couldn't hold it. Ended up with a 54.8 average on the first leg, 55.8 on the second leg, and 55.7 on the third leg. I thought I was doing okay... well enough to at least claim 1.5x EPA (54 mpg). Boy was I disappointed when I filled up, did the math and saw 49.92 mpg!

But, my buddy (the only other person who showed up!) had a better day in his Sentra. He's got the bad boy Sentra SE-R Spec V, 2.5 with a 6-speed. He wasn't planning to compete, but we talked last night and after he complained of never getting more than about 32 mpg out of the car, I assured him that based on the EPA figures, I was sure he could get at least 38 mpg on this trip. We talked about hypermiling techniques, and he tried a few on his drive home and found that they do indeed work... very well. He was inspired, went to bed thinking about it, and was STOKED in the morning, ready to run!

He attacked the event in his typical style. He's "all or nothing" when it comes to competition. So, he removed his back seat and some other weight (he's got the stuff unbolted already for racing), taped his grille, and proceeded to hypermile the hell out of the Sentra! He was trying WAY harder than I was, and he deserved the "win" in today's event. He returned 41.7 mpg out of a car rated at 27 mpg highway. Over 1.5x the EPA. Impressive, indeed.

He did it mostly by using FAS and extreme pulse and glide. His car has enough torque to accelerate pretty easily from 30 mph in 6th gear. So, what he did after some experimenting was accelerate up to 60-70 mph (depending on the road), kill the ignition and neutral-coast down to 30 mph (traffic permitting). He put my 10-15 mph pulse & glides to shame!

So, I guess I need to master FAS before I try another economy run.

Coolest thing today... I pretty much drove for 6 hours straight with a couple little breaks and only used 3.6 gallons of gas that I paid $2.01/gallon for. Where else can you get 6 hours of entertainment for under $10?

[Sodium Duck]

See? =] wacka wacka wacka!

[Loren]

/thread

[Bob_VT]

Great try Loren. It appears as if we have a goal.

[voodoo22]

I've noticed that going as feather light on the gas pedal under most circumstances makes a bigger difference than you might think. I've seen video of the top Prius drivers in the world using only their big toe on the gas pedal while wearing socks or going barefoot so they can really feel the throttle. I still wear shoes while driving, but with my driving style if I am not thinking about backing off the throttle and using as little pressure to maintain speed in most situations, I will lose 2-4 mpgs. I already have a light foot, so I could see this even making more of a difference for people with a lead foot.

It's all conjecture, but I think going feather light allows you to know when you can coast or going into DFCO quicker and also allows "hangtime" to kick in as much as possible.

I don't know your driving style Loren, but I think you should try focusing on this as well if you think you could go lighter on the throttle.

[Loren]

It's funny... when I autocross, I have a big bag of excuses that I'll pull out as necessary. But, I don't feel the need to make excuses here. I guess it's because this is so much more "scientific" than autocross. It is what it is.

That said, I will admit that I *did* lean on the throttle too much during a good portion of this run, and wasn't as focused on it as I should have been. But, I have an excuse! Mainly, it comes down to traffic on about half the route (the faster parts, where economy was already taking a hit). I was leading, Jeff was behind me in his Sentra, and he usually kept a good distance, but as mentioned, he was P&G in an extreme fashion. I tended to stay around 50-55, where he would pulse to 70 and charge up behind me, not starting his glide until he was a good 20 feet from my bumper. Not a problem, but it caused me to always have to check my mirror to see where he was when I wanted to start a glide.

Couple that with some impatient (yet dumb enough to NOT take advantage of many opportunities to pass) traffic behind Jeff that caused me to try very hard to keep my speed up to very near the speed limit... I guess I shouldn't be surprised at the outcome.

And I wouldn't have been, had that been what the ScanGauge was telling me.

Oh well. Next time we'll ditch "realism" (I really did want this route to go through some city traffic as well as rural 2-lane highway traffic) and go for TRULY rural roads, practice some serious P&G, and see what happens.

The good news is that my buddy Jeff is hooked, and he never backs away from competition. All I have to do is say "bitch, I want a rematch!" and I'll have a solid competitor ready to go play.

[enkid]

Actually, I think you got pretty close to the upper limit under those conditions.

If you did an average of 35MPH, you'd probably have gotten better than 55MPG.

I average about that speed on my commute. I was surprised it was that low after I got my Scangauge.. Intuitively I would have guessed it was 45MPH.

[Loren]

Our target was an average 45 mph on this run. The 180 miles was split into three sections, and we finished 3-7 minutes late on each of them. Overall, our average speed ended up being a little over 38 mph.

I think 49-50 is about the max for the techniques that I've mastered. To get more, I really need to practice longer pulse and glide and incorporating FAS to extend the glide.

I still think there's 55 mpg out there.

[50MPGDream]

Originally Posted by Loren

The ScanGauge was telling me that I was getting close to 56 mpg. It peaked at 56.2 at one point, but couldn't hold it. Ended up with a 54.8 average on the first leg, 55.8 on the second leg, and 55.7 on the third leg. I thought I was doing okay... well enough to at least claim 1.5x EPA (54 mpg). Boy was I disappointed when I filled up, did the math and saw 49.92 mpg!

woah! did you get fuel at the same pump you went to last time you filled up? my SGII has never been that far off. what correction % are you at?

[Loren]

Originally Posted by 50MPGDream

woah! did you get fuel at the same pump you went to last time you filled up? my SGII has never been that far off. what correction % are you at?

I did fill at the same pump. I've just finally wrapped my head around the correction thing, and I'm sure it was screwed up. I'm experimenting with a 6% correction factor right now.

My correction may be more than normal because I'm running tires that are about 1% shorter. I have to correct my calculated mileage for that, too.

I'm trying to get it to where the ScanGauge reads slightly LESS than actual MPG. I would prefer it to be off in that direction.

[Tonavi]

Originally Posted by Loren

I don't normally cut the ignition at stop lights, but I will for this trip. That's probably worth another 1/2 mpg or so, maybe more.

I've heard higher octane can improve mpg a little. I'll be at about 1/2 tank before Sunday, so I'll have half a tank of 87. I guess it wouldn't hurt to fill up for the run using 91 or 93 octane. Will probably average to about 89 octane.

Any other ideas on how to get that last little bit of MPG without getting too crazy?

I used to stop the motor at long lights but noticed a decrease in mileage. The amount of gas the computer uses to restart the engine undoes any benefit. Also, the added wear and tear on your starter does no good. Unless the light is >10 minutes, there is no benefit to doing this.

Using 89 octane gas is what I have been doing ever since 600 miles, and I have went from getting 38 MPG to about 44 with the same driving style.

Good luck on your trip!!

[voodoo22]

Originally Posted by Tonavi

I used to stop the motor at long lights but noticed a decrease in mileage. The amount of gas the computer uses to restart the engine undoes any benefit. Also, the added wear and tear on your starter does no good. Unless the light is >10 minutes, there is no benefit to doing this.

Using 89 octane gas is what I have been doing ever since 600 miles, and I have went from getting 38 MPG to about 44 with the same driving style.

Good luck on your trip!!

This simply isn't true according to everyone elses data. The general rule is if the stop is longer than 7 seconds on the Yaris (and most newer cars), the amount of fuel saved makes up for the extra wear on the starter and still saves you a few bucks. I don't have a scan gauge, but after I started shutting down at the few long lights I deal with, my MPG went up and so has everyone else; who's wrote about shutting down at longer lights; except for you.

[Tonavi]

It could be that I did it at almost every light (the lights here are long and go red even when nobody is coming) for about 2-8 minutes, depending on traffic. Maybe repeatedly using it causes a decrease? Either way, I started taking the highway more and letting it idle at the shorter lights or when I'm first in line. When it's cold out, mileage usually decreases 20-25%, but I have been able to minimize this to only 10% with this method.

[BailOut]

Hello Tonavi,

As voodoo explained all it takes to break even with the fuel usage and wear and tear of a warm start in most modern vehicles is 7 seconds of idling. This has been proven time and again, with every type of vehicle, fuel, drive line, transmission, etc. All variables have been tried and found true. Hybrid cars are designed to perform this function for you.

If you are seeing opposite results then either your MPG measurements are not accurate, your MPG measurements are not done consistently, you do no have enough data to get a clear picture (e.g temperatures, wind conditions, etc.), your personal perception is skewed for some reason or something is mechanically wrong with your vehicle.. I encourage you to begin keeping an MPG log and tracking some good data points while you experiment with the technique some more.

[voodoo22]

Brian is the man. I used his write ups to confirm and learn a lot when I started to take getting good FE more seriously. He knows his stuff and should be respected for not making unsubstantiated claims.