What can I do TODAY on my Sunfire? (mods for 2000 mi round trip)

[some_other_dave]

Two very quick mods you can make that should help:

- Air up the tires. Unless they are old and need replacing immediately anyway, going up to the sidewall max should help lower your rolling resistance and should not hurt the tires. You can use lower pressures than that if going that high makes you nervous, but a pretty good body of anecdotal evidence says sidewall max is fine.

- Slow down. Limit your max speed, and try not to change speed any more than is absolutely necessary.

-soD

[GMPG]

I got the air dam, hood cowl and grille blocks done and then took the car out for some tests while it was still light. Note that I did NOT adjust tire pressure before this, I'm still at the 34psi I normally run. I'll be changing that to 38-40psi in the morning before I leave.

I'm going to pack the car now and then if I have time I'll knock out some simpler rear wheel spats... duct tape is a wonderful thing.


Coast down:
42.56 seconds from 60mph to 35mph.
-------
45.24 seconds from 60mph to 35mph with mods
-mods, upper and lower grill block, air dam, hood cowl.

2.68 seconds longer to coast down

Hill Coast, Stock:
Entry marker 55mph
Mid point 62mph
Exit point 55.5mph

Hill coast with mods as above in this post.
Entry marker 55mph
Mid point 63mph
Exit point 57.5

Up 1mph at the mid point and 2mph at the exit. I also was rolling several mph faster when I hit the 35mph sign coming into my town that I normally hit right at 35mph while coasting.

[GMPG]

Originally Posted by UltArc

When people come here, ans say they have been lurking, I always wonder if they really have been. And then some people make a comprehensive list of their plan, ideas, so on, and it is evident they have been, and are genuinely interested.

I like to read first and then post all my noob questions. Heck, I might even come back later and post my MPG findings!

[mcrews]

Originally Posted by UltArc

When people come here, ans say they have been lurking, I always wonder if they really have been. And then some people make a comprehensive list of their plan, ideas, so on, and it is evident they have been, and are genuinely interested.

So I can whole heartedly say welcome, we are glad to have you.

you have been lurking for a while lol

Ditto!!!!!!

Lurking
Reading
Planning
Doing!

[mcrews]

Go to 44psi

[MetroMPG]

Well, I guess you left this morning. Hope you have a safe journey (& good fuel economy).

Post pics & results if/when you get a chance!

[UltArc]

Originally Posted by mcrews

Go to 44psi

I go 40% above max. 56 on 40 max. But the tires are brand new. I am not saying everyone should do it, just noting that on new tires, I have had no trouble going 40% over.

[GMPG]

Pics: Pictures will have to wait until I find the "safe place" where I stuck my SD card... best way to lose things it to store them safely it seems...

Before I left on my road trip I installed a full upper grille block and a 90% lower grill block. I left a small opening in the center of the lower grill block that was the width of the license plate and about 2in high. I also installed an air dam that came to about 3.25in above the ground.

Here are some mileage numbers from the trip down to GA and back to NY.

The first tank was 12.2 gallons for 465 miles or 38.11mpg, already a best ever mpg for this car even though it started off with 20mi or so of semi-urban driving. (Binghamton, NY to Roanoke, VA)

The second tank I'm missing the note with the miles and gallons but it had worked out to 39.05mpg! (Roanoke to near Chattanooga, TN)

The third tank took me from Chattanooga to Atlanta with a good dose of ATL driving/five lane parking. 179.9mi for 5.06gal or 35.55mpg which is about on par with my previous best highway miles before aero-mods.

Fourth tank took me 485mi from Spartanburg, SC to Chambersburg, PA on 12.8 gallons for 37.89mpg. This included a roughly 25mi detour off the highway onto back roads with an approximate 1200ft climb over 12ish miles. From i81 to the VW/WV border to camp for the night. Being small and twisty roads I was only able to regain part of the loss from climbing.

Fifth tank is the charm! Chambersburg, PA to Home, NY covering 299mi with 7.4 gallons for 40.4mpg! WOOO!!!!!

Obviously these were all fill ups at different pumps but all mpg figures were within .25mpg of what the Ultra Gauge said as well so I feel like I can honestly say I met and beat my 40mpg goal for this car.

Also keep in mind that this was NOT eco driving, or at least not more so than the way I've driven for years. I'm usually about 5mph over the limit, draft casually where I can and coast down long hills. I wanted to hit 40mpg without drastically altering my driving style or schedule. I know I could do much better at a slower speed, even keeping to the posted speed, but that wasn't the goal here.

I will SURELY be doing some mods to my Jetta although I doubt I'll be duct taping #$@& all over the nose of it.

I should be posting pics up by mid week, I'm pretty sure my SD card is rolled up in a tent...

[MetroMPG]

Congrats on meeting your goals!

[GMPG]

Thanks! It looks like the car may be staying in the extended family so I'll probably work on the rear wheel skirts a little more and try them for a couple of tanks with the other mods. It'll be comparing local to all highway driving but I'm still interested to see what the numbers are.

Subjectively I'd say the biggest window for better fuel mileage with the mods I have now is in "draft coasting". On pretty much any highway downgrade I can coast for a looong time with only the slightest draft, like two cars ahead of me. No practical way to do an A-B-A comparison of this but I know the car well and typically draft/coast downhill on highways and the car is clearly picking up speed on more gentle grades and holding speed much longer with or without a draft... with a draft though it's kind of ridiculous. Pulse and Glide is also a winner with this setup.

I don't know if I can "fix" this or not and I doubt I'll try since I'm selling the car but when in motion the ECU doesn't want to let the engine idle below about 1300rpm so the fuel savings while coasting could be even better if I found a way to let it drop back to the "at rest" idle.

Oh, I did have some engine temp issues that I'll discuss when I post pics. Nothing major but some refinement to the lower grill block would probably solve this.