Long trip ahead; 70mpg tank goal with Helga (Jetta TDI)

[AndrzejM]

NachtRitter,

Impressive preparations comparing to two pieces of cardboard I put on Berta before my trip to Prague, but again I wasn't counting for 70+ MPG tank. Can't wait to see the actual numbers from your trip.


Ausias,

I can't see the images. And one more thing:

cd lowered from 0.31 to 0.25

Can you give us some more details? Are you talking hypothetically just for doing some match purposes, or actual Cd number of one of your cars?

[NachtRitter]

Auff! Finally Helga is back on her tires. And I'm very sore. Some of those suspension bolts require quite a bit of strength to torque correctly.

Drivers side axle has been replaced, as has the drivers side strut and spring.

That big nut on the end of the axle is pretty tight already but will need to really torque it down once the weight is on the wheel.

While she was up on the stands, I also changed the oil and put the exhaust pipe on.

I'm pretty pleased with how well the pipe fit... the outlet is closer to the bumper than the stock muffler, which required a little bit of a trim of the valance. But this is what I wanted, with the hope that the soot would be ejected further back and thereby allow less to deposit on the rear of the car.

The other thing I did while the car was up is put a belly pan from rear axle back to the rear bumper. Sorry, no pics at the moment. It was a late decision; not something I'd planned to do originally. I looked at the area, had a nice big sheet of coroplast, had an idea about how to secure the coroplast, and decided to give it a try. We will see if it helps.

After the underneath stuff was all done, I put Helga on her tires, tightened the axle nut, checked the other nuts & bolts, and went for a test drive. She sits noticeably lower and feels pretty tight, not bad at all. The exhaust sounds fine too. Definitely can hear the turbo better, but can't tell a difference at all at cruising speed.

Andrzej - I liked your taped-on cardboard! It probably helped quite a bit. I would do it too if I could get away with it. I think it is a good opportunity for additional FE gain, but it will have to wait until I can put some time into it so I can make it look nice. Maybe for next year, when my goal can be a 75mpg or 80mpg tank?

Ausias - I'm also interested to know how you lowered the Cd. For me, the 5th gear swap was an easy decision... I already had to remove the transmission to replace the clutch; it was maybe 15 extra minutes to replace the 5th gear... very easy! For the 6th gear kit, it can be done without removing the transmission, which is why I like the idea... but for right now it is only in my thoughts... no plans yet.

[NachtRitter]

Taking off tomorrow with a goal of a 70mpg tank somewhere along the trip. Grabbed the elevation profiles from Google Earth for my route 'to' and the route 'from' St. Louis. Decided to take Hwy 50 to Interstate 70 to get there (wanted to go through Colorado once) and then will probably take Interstate 80 to come back home.

Hwy 50 / Interstate 70 elevation profile:


Interstate 80 elevation profile:


I'm thinking that my best chance to get a 70mpg tank is going to be on the last day of driving 'to' St. Louis.

[AndrzejM]

I've learned that driving wisely through the mouintains can actually save you more fuel than driving through a flat area. And of course with DWL not P&G (the way I'm driving).

I see that you're well prepared for the trip.

[Xist]

Originally Posted by AndrzejM

I've learned that driving wisely through the mouintains can actually save you more fuel than driving through a flat area. And of course with DWL not P&G (the way I'm driving).

I see that you're well prepared for the trip.

My parents live in mountains and I actually get better mileage driving up there than I do on the freeway here and I do not accelerate past fifty-five.

Before, with manual transmissions, I usually stayed in fifth gear and lost a little speed going uphill--there are two lanes, so I am not blocking anyone. The lighter the traffic, the sooner that I coast to the crest, and I coast down until I need to shift back into gear to control my speed.

Sadly, this car has an automatic, so I accelerate uphill just short of the shifting point, and slowly lose speed.

There are too many twists for me to consider engine-off coasting when I have another manual transmission.

The last time that I drove back, I tried pulse-and-glide, but my Ultragauge did not show an improvement, although it seems to make a small difference down here.

[NachtRitter]

First two days went well. T'stat is keeping temps at about 213* F, with max at about 222* when climbing. The Diesel engine is running smoothly. The missing muffler is not noticeable at all. Suspension feels much more controlled with the new shocks. The axle-back undertray is staying put, nice and solid. Can't really say much about the FE since the past two days have involved mostly climbing, mostly gradual and some steep. However, the FE after 1 1/2 days of driving was 62+ mpg with an average speed of 60mph. I don't know how that compares to anything, but I certainly can't complain about it much!

Got past the peak of 11,992 feet altitude yesterday evening, and the rest of the trip is basically downhill... the Scangauge is currently showing over 67mpg, which even includes the climbs up to several summits, so the tank FE is looking pretty good.

[AndrzejM]

I think you'll finish with 70+ tank... And that's great! Keep us posted on the progress. I'm still keeping my fingers crossed for you.

[NachtRitter]

Thank you! But sadly, it was not to be... crossing the plains of Kansas, the head/cross winds were fierce, gusting up to 40mph according to the weather report... yikes! Then by the time we hit Missouri's rolling hills, I was too tired to take advantage of them... both sapped the FE until I was down to 64mpg by the time I filled up.

Two days of no driving, then I'll be heading back home and making another attempt.

[AndrzejM]

It reminds me of my trip from Sofia to Bucharest, the wind was blowing so hard that gliding wasn't an option at all. It was like breaking with an engine. Hopefully you'll meet that wind again on the way back blowing from behind. Then you'll see numbers growing up to 70+

Can't wait for the results. But now I can let my finges to rest a bit and I'll keep them crossed again in two days. Enjoy the weekend and have a safe trip back home.

[elhigh]

Originally Posted by NachtRitter

Thank you! But sadly, it was not to be... <snip>the head/cross winds were fierce, <snip> by the time we hit Missouri's rolling hills, I was too tired to take advantage of them... both sapped the FE until I was down to 64mpg by the time I filled up.

Two days of no driving, then I'll be heading back home and making another attempt.

The guy's getting his best FE since this time last year, and he's disappointed.

I'm telling ya, racers got nothin' on hypermilers. Racers say faster isn't fast enough, 'milers say farther isn't far enough.

Good numbers anyway, and better luck coming home!