TopGear.com America high mpg project (regeared, aeromodded diesel Rabbit)

[jamesqf]

Originally Posted by mtgeekman

I believe the video says 70mpg.

70 mpg? They think 70 mpg is high? (ROTFL) I get that in my 2000 Insight, doing most of my driving in the Sierra Nevada.

[tasdrouille]

70 mpg without a reference point can be high or low. 70 mpg for a TDI is considered high, but it still depends on the speed you're driving. An ALH TDI in a rabbit driving 40 mph on a flat road with no wind and pumped up tires will hit 100 mpg steady state for sure.

With the AHU (same engine but with a non VGT turbo, so more restrictive) in my mk3 jetta with winter tires at 55 psi, I was hitting 90 mpg steady state at 40 mph. The mk3 jetta is a lot heavier than an early rabbit and have a bigger frontal area. But I had a much better Cd though.

If it's a rabbit with a TDI transplant, I'd throw a propane kit in it. Anyone ever saw that video of a stock golf mk3 fitted with propane keeping up with a NSX in a drag race?

[Sean T.]

Uhm there's a link in the video page...

We Build a 70 mpg Car - Top Gear US

[SuperTrooper]

Originally Posted by jamesqf

70 mpg? They think 70 mpg is high? (ROTFL) I get that in my 2000 Insight, doing most of my driving in the Sierra Nevada.

I've always been curious why you don't keep a fuel log here jamesqf. 70 MPG would make you the top dog Insight.

[MetroMPG]

Originally Posted by Sean T.

Uhm there's a link in the video page...

Yep - they just posted it today, as foretold.

Looks like an updated version of Car & Driver magazine's "Crisis Fighter" ecomodding series from the 70's, eg. the Crisis Fighter Pinto ... except with a much bigger budget!

From the TG article:

Step 1: We'll buy a 1981 Volkswagen Rabbit Diesel right here in New York City.

Step 2: We'll drive it across thousands of miles of frozen tundra to Regina, Saskatchewan, where CWS Tuning will skillfully replace the clattery old oil burner with a modern, computer-controlled, turbocharged VW TDI engine.

Step 3: We'll head south to sunny Southern California to thaw our bones and have UCLA aerodynamics professor John McNulty show us how to make a brick slippery.

This will be interesting. Thumbs-up, Top Gear.

[Daox]

I'm gonna need more info before I'm impressed. Drive that Rabbit slow enough (not even all that slow) and you'll hit 70 mpg pretty easy.

[SuperTrooper]

Modern TDIs are marvels considering they are hauling around cars weighing almost 3k pounds. The 1981 Golf weighs in under 1900 pounds. Getting to 70 MPG will be the easy part. The hard part will be the 7 second 0-60 to happen. High torque FWD cars are a handful and it will be difficult to get enough tire under the car to handle both high torque and LRR.

[tasdrouille]

7 secs 0-60 in a 81 Rabbit with a TDI ALH engine (I'm pretty sure that's they engine they'll be going for) won't be too hard to achieve from a power standpoint. On a mk4 body, more or less 180 hp, which calls for a bigger turbo, bigger holes and pump, is required to make it in the 7s. With the rabbit, just a tune bumping the power from 90 to ~115 hp would probably be enough given the huge weight reduction. Throw in a set of .205 nozzles and it's a sure bet.

As you said putting that power down will be tricky. I'd throw an LSD in there. It would make the car even more fun to drive overall.

Darin, a proper street tune should not smoke under any circumstances. Problem is you have to sacrifice that last bit of power in order to be smokeless when you put the pedal to the metal. Lots of people getting tunes feel it's ok to have just a small haze at wot, but they're often the kind of people who gut their cat too...I hope top gear does not go there.

[giff]

We're pumped to see the effort that went in to your (very educated) guesses. Kudos, obviously, to everyone who said Mk1 with a TDI.

Some of you already posted the links, we're glad to see the enthusiasm, but here they are anyway;

Check out the video of the car in all of it's stock, clanky, stalling glory here;
Watch Efficiency Meets Fun - A Top Gear Car Video - Top Gear US

And look at the feature, with all the details here;
We Build a 70 mpg Car - Top Gear US

We'll be back, and are really enjoying your comments. Hope to keep you EcoModders entertained =)

[MetroMPG]

Originally Posted by Daox

I'm gonna need more info before I'm impressed. Drive that Rabbit slow enough (not even all that slow) and you'll hit 70 mpg pretty easy.

Nail on the head. 70 mpg sounds impressive absent any kind of context. Are we talking highway mileage? Someting approximating EPA city/highway combined? Steady state 60 mph?

If you're going to knock the Prius or Insight (which TD will gleefully do!), it needs to be a fair comparison. Not "ideal conditions" against EPA.

Despite the fact that the vast majority of sites that picked up basjoos' "95 mpg" Aerocivic ignored the details around that figure, he did explain the conditions on his site under which he was able to achieve that.

EDIT: not knocking the project. I get a kick out of seeing "mainstream" media doing stuff like this for an audience that probably doesn't give a rat's... about efficiency.