Depressing Stats....does the weather really matter that much
 

Im very new at this, and was feeling great about the gains acheived with aero mods alone. My best tank has been just over 26mpg.

With all mods in place, I was testing at 25.5mpg on a test route.

Now, rain and cooler weather have set in and I only get 20-21 on that stretch of the test route, if I work really hard at it.

Does the weather really have that much to do with my FE? Im really down about the losses over the weather...its discouraging at best, and makes me wanna forget the whole thing at worst. :(

How long is the test loop and are you up to temps when you start it?

Weather has a lot to do with it, :p, I am tempted to think more so on a big truck that's gotta move a ton of rain/water to get around.

Air temp matters and so does rain. I got my best tank when it was raining for 3 of the 5 days thought i wonder what it could have been if it was nice out.

yep - up to temp, and the loop is 18 miles.

I even installed a quick hot air intake, restored the IAT to 120-130, and still only got 21. sad sad sad.

thanks for the input!

Pull all the mods off and drive like everyone else ta put it in perspective. ;)

you know, I have thought of doing just that... i think i might, just to see what all this is doing for me under these conditions. Thanks for the nudge in that direction!

Np. I have no mods on my pickup, but the *one time I decided to drive 55/65mph instead of the usual 40/55mph over a route I do every couple weeks, the difference was huge! Assuming 30mpg@50mph compared to 23mpg@60mph, I'm nearly paying an extra $10/hour to get there an extra ~17% faster.

*6/16/06

On the flip side, if you hadn't done the aero mods you'd be getting 14-15 MPG in the rain ;)

Well, Im throwing in the towel on the F150 - complete waste of time to me at this point.

I removed the side mirrors in an effort to improve things, went on the test run, and got nill out of it. Very irritated, I decided to take the advice above and remove everything....

I took EVERYTHING OFF except the bed cover. NO airtabs (except on bed cover), NO grille blocks, NO well or wheel covers, deflated the tires to 40psi, reinstalled the wipers.

I used the SGII to drive the way I always do on these routes, cruise control on flats / coasting on the hills.

I got 21.0 / 21.3 / 17.8 / 21.5

So it appears that most all of my gains are from driver adjustments based on SGII - and everything else is negligible.

All mods are off and will remain off...disappointing reality, but they apparently dont help as much as I thought they did.

Will be interesting to see how the trip to baltimore next week goes. If I pull a 24-26mpg with no mods, just changed driving behavior - this will be confirmation for me.

Im seriously seriously considering dumping the F150 and getting a smaller car...but will see, the wife is concerned about safety reduction (and I tend to agree).

Take care all, its been fun.

I bet you could sell some of those Air Tabs to interested parties on this site.

Have you taken into account winter fuel changes...also an 18 mile loop is very hard to use as a definitive calculation. It only takes a 1/10 of a gallon to shoot mpg figures off the wrong direction.

jeffrey, wait a year or two until the smaller diesels come. If my Santa Fe had the 2.2 CRD they sell in the rest of the world, I'd have probably never even visited here and I'd be getting high 30s or more on the highway!

It's too bad you couldn't have had your truck run in a wind tunnel. Your aero mods were very well executed but that's the only real way to test them.

You definitely got me thinking of something for my roof transition...

Good luck, whichever direction you take.

I am going to attempt to return them all for a refund first, if that doesnt work - look for them here late next week...

I just got 28.4 mpg in the Saturn wagon (a lowest ever). I think that they probably switched over to winter blend gas. Also, I had a bit of road rage and floored it for a few seconds once.

Jeffreymccoy - just look to my sig for all the answers. :D

But in all reality, I'm eager to get some LRR tires for my car. I think that's the simplest and greatest single thing you can do for results. Taking off the side mirrors and expecting a noticeable change is unrealistic. Most of those things by themselves (except tires and some extreme aero mods) will make a noticeable difference in your FE.

As far as safety. Bah hum bug. Everyone would be safer if these large vehicles didn't exist in the first place. It may be safer for you and your wife to drive that car, but what about the rest of the people on the road in smaller cars? It's not safer for them! That is one thing that is really a bee in my bonnet, cars get bigger and bigger trying to out do each other and be "safe." But it just ends up making everyone less safe on the road. The safest car you can be driving is a medium to large car that is not an SUV or truck. Get a Toyota Camry. Safest and best FE bet. Or get a 2WD Toyota Tacoma 4 cylinder. The vehicles that are higher off the ground are unsafe for everyone involved. They flip easier and they kill more people in other cars when colliding with them.

This was my thought from the very beginning. I'll dare say you could get a smaller car that's safer than the truck. The new honda accord has been getting rave reviews and from what I hear is very safe.

I have seen the light - yes this is the real answer!

I agree with you, but reality is that they do exist and will for a long time.
Since the above is true, and while I do care about other people, I naturally care more about my wife and kids. If it comes down to me or them, I'll choose them to loose that battle every time...

Only if the SUVs / trucks didnt exist, but as already established - they do.

I didnt buy the truck for this, I needed it when we moved into our house for all the landscaping and projects that were on the plate. They are all done now, and I dont see the need for a truck like I used to..which is why I consider the change. Now that I am considering it, the less safe factor comes into play.

Back to my original problem... cost. The truck is paid for, and I cannot justify a loan of anything more than 4000. It costs me the same to drive the truck as it would to drive said new car + car payment for anything more than that. This puts a new car, even a base civic or fit just out of reach of being a financially sound decision.

So now Im looking at some options that are 06 or 07 models, but used cars frustrate me for some reason.

Where do you live again? You could buy matt (the site owner's) fit, :p

That was gonna be my other recommendation over the Camry. I think the Camry gets better FE tho. Lemme check. They're about the same. 25 combined.

Altima is also a larger car that is good on gas. Wow, significantly better than both the Camry and Accord.

What you really should get is a Camry Hybrid or an Altima Hybrid. Both use Toyota's Synergy drive. If you go non hybrid I would definitely get the Altima 6 speed 4 cyl with a very respectable 32mpg highway.

New EPA MPG Info

New MPG tests are more realistic New tests include cold temperature operation, air conditioning use, and higher highway speeds.

2008 Honda Accord
Regular Gasoline
22
City

25
Combined

31
Hwy

2008 Toyota Camry
Regular Gasoline
21
City

25
Combined

31
Hwy

2008 Nissan Altima
Regular Gasoline
23
City

26
Combined

32
Hwy


2008 Nissan Altima Hybrid
Regular Gasoline
35
City

34
Combined

33
Hwy

Toyota Camry Hybrid
Regular Gasoline
33
City

34
Combined

34
Highway

Edit:
The 2.7L Toyota Tacoma has much better gas mileage than your F150. You have the 6 cylinder auto with that F150? Your combined is 16mpg where as the Tacoma is 22. Tacoma has 20 city and 25 highway. You could sip it to 29 no problem. (wow, seems really good for a pick up.)

The new camry has a few bugs in it and has caused toyota to slip to 3rd on new car reliability, honda is now first, hence my suggestion of the honda over the toyota, :p

Anywho, if he's not shopping new then that opens up a whole new can of wurms.

Wel, I'll find him the right car for his needs if he gives me budget and purpose.

I think maybe you are jumping the gun a bit...more testing over a longer period of time/distance is needed. A paid for vehicle is already running much less $/mile that even a new/used not paid for economizer...or close to it.

I was wondering if the Air Tabs hurt in wet weather because they are now not only directing air but also water...which is much heavier? Just a thought. I think you were on the right track and just need to stick to it for a while longer. Perfect your driving techniques and don't expect miracles. I like the idea someone had about magnets on the bottom of the Air Tabs to make them easy to relocate and test.

It's kinda sorta true and depends on your driving conditions. Trucks/SUVs are a double edged sword in that they are safer in collisions with smaller vehicles, but more dangerous in solo run off the road accidents or accidents involving something bigger than they are. So, overall, larger vehicles do little for occupant safety since they are as dangerous in some accidents as they are safe in others, but overall increase the risk for everyone else. That being said, if ya drive the vehicle in mostly crowded/slow city, then it may be safer than a smaller vehicle, however if ya use it for open highway, it may be more dangerous. Like everything else, YMMV.

Your truck is not necessarily safer for your kids and family because of it has a high center of gravity. The reason I recommend a Camry or Accord is because these cars are not likely to flip - much less likely than your F150 - and they are big enough to be safe while still maintaining decent FE. I think the whole safety thing with big cars is more a perception thing than anything else. You feel safe in your F150 --and have become accustomed to the dominance over the road it has given you, and going into a lower to the ground car will make you feel less safe. But the reality and the perception do not correlate.

Thanks for those words of insight regarding the safety issue. Will see how this goes. Im in deep contemplation at the moment.

I can personally vouch for the safety of medium/large cars versus SUV's/Trucks. A few years and a few cars ago, I had a '94 Olds Cierra that died rather violently when I got T-boned in the driver side door by an Explorer doing about 35 (I was doing about 40)
By all accounts it should have been a really bad accident, but I got out without a scratch thanks to the side-impact beams in the doors. I know it's kinda hard to take comfort in the fact that all that lies between you and the steel bumper of a 5000lb behemoth is a strategically placed steel tube, but I now know that that little steel tube works like a charm. I feel very safe in my little civic now that I know it has side-impact beams in the doors.

I just have to add the safety of a vehicle is directly proportional to the temperment and skill of the driver...

For some real-world safety information see www.iihs.org.
International Institute of Highway Safety.

Among other things, they rate safety by actual stats of numbers of people killed in accidents in different models/years cars. They measure deaths per millions of cars so a model selling ten times as many cars gets rated on an even playing field with other models.

Not the thing to read if you get all upset over turning highway deaths into statistics. But you really see which models win and lose.

jeffreymccoy -

I find the "regular driving" tests make it hard to quantify mods because all the other parameters add up (weather, traffic, cargo weight, me, etc ...). Over time I think I have gotten my normal commute "down". The problem is, for certain mods that have only a 1-3% effect, normal driving can't give a clean answer because they are overwhelmed by everything else.

Question for someone else (basjoos?) : What's the cleanest MPG test you have seen on this site? For aero mods, it's the "coast-down a hill to a stop" test that is best, right?!?!?!?

CarloSW2

DarbyWalters -

Yeah, I keep thinking that it's close to 90% of the safety factor, but I don't have any numbers.

CarloSW2

brucepick -

In another thread, I think the gist was that head-to-head, an SUV obviously beats the smaller car, but the overall safety of the SUV was so much lower that the SUV owner was still less safe in general (rollover, losing control in emergency maneuvering, etc...).

CarloSW2

High (very) speed coast down w/ a video cam on the dash for decent speed/time accuracy imo. Coasting to a stop can add a lot of error since the time from 30-0 is generally way more than the time from 60-30, so the difference in two profiles is harder to spot. It may be ~21s/23s compared to 6s/8s and there's a larger window for other stuff like weather to influence the results. At 90mph an average'ish car may need ~24kW for aero and 6kW for rolling. At 45mph it's only about 3kW for each, and a ~23mph it's only ~.3kW for aero and 1.5kW for rolling. The slower we go the harder it is to pick up any difference in aero. And... to complicate things, I think (this right treb?) the drag coefficient changes compared to speed, so that's just one more variable, although Iono if it's significant for car speeds. In any event, a 12% improvement in aero will result in ~27kW needed at 90mph versus the usual ~30kW, but at 45mph the difference is only~5.65kW compared to ~6kW, and at 23mph it's pretty well unpossible to figure a difference. Ideally, we could all get together and head out to the salt flats w/ a cam to do some timed decels. Newbs are limited to 140mph max speed IIRC and have to have all the safety equipment, but I'm sure 120-100mph could give us tons of great data on how certain mods influence certain cars. And, for a car like my veedub, that's gonna be limited by power, the top speed may be noticeably higher if the mods are as effective as we think they are.

gonna buy an 08 fit I think...getting a good trade value on the truck, so what the heck.

why is Matt selling the fit though? Whats wrong with it - quick before I buy one....lol. THanks.

He's gonna buy an insight, :p