Rotten Passat - Fuel Economy, Hypermiling, EcoModding News and Forum

dfeldt91 · 05-31-2016, 06:15 AM

Stock Weight: 3043 Pounds
Current Weight: 2660 Pounds
Total Weight Loss: 383 Pounds

Goal: 2500 Pounds (18% weight reduction)

Stock Power: 150 HP
Current Power: 242 HP

I finally got around to gutting my 2001 Volkswagen Passat 1.8T for MPG's. The car gets 21/29 MPG EPA. My goal is 200% EPA on highway and 150% in city, so 58 and 32 MPG.

I have many aero mods planned in order to reach my goals. I've already installed what appears to be a more aerodynamic front end off a newer model Passat. I'll be adding a grille block, deleting external mirrors, creating a rear trunk extension, somehow dealing with the low pressure spot on the rear window, lowering the car, doing some wheel covers. an under tray, and a few other little things that will add up to reach my goals.

Here are a few photos of the Passat:

Notice the wheel gap from removing 325 pounds. Coilovers are definitely in the works and are about a month out.

Will be removing the trunk shocks as I do not use the trunk for its purpose now. Every ounce helps..!

Rear seats, interior, etc, it all had to go. I have adjusted my dating life to exclude women with kids or ex baggage. No room for them now :P

Rear shelf and sun block were removed, this area that can be seen in the photo will all be removed when the roll cage goes in since the cage will stiffen it even more.

I removed a ton of weight from the rear doors. No speakers, window motors, etc..

Lots of extra wiring that was removed from the radio/amp/airbags. Amp wiring will likely go back in if I can find the wiring in the dumpster I threw it in unless I get an aftermarket system since it will be lighter and allow me to remove the front door panels and innards...

2850 with me(120 pounds) in the car as well as 5 quarts of oil and some clothes.

The following is a list of everything I have removed from the car thus far:

A/C Compressor/Radiator/Lines/Bracket/Tensioner
Air Box/Intake/Filter/Cover
Arm Rest
Engine Cover
Floor Mats
SAI Pump/Lines
Rear Seats/Belts/Head Rests/Brackets
Front Bumper Reinforcement
Spare Tire/Jack
Windshield Fluid Reservoir/Lines/Pump
Carpet from entire car
Center Console
Rear Door Cards
Pillar Covers
Rear Seat Brackets
Rear Door Inner Metal
Heater Core/AC Core/Fan/Box/Tubing
Side curtain airbags
Passenger Airbag
Rear Shelf
Headliner
Pillar Covers
Lower Half of Dash
Radio system
Muffler
Installed Drilled/Slotted Rotors

I still have to remove:

The entire dash
Hood Insulation
Wiper – Passenger
Sway Bar
Floor Tar
Door Support Beams
Rear Bumper Reinforcement
Spot Welded Brackets/Excess Material

Other planned modifications include:

Different Wheel/Tire combination
Cut out trunk and hood support metal
Coilovers to get rid of the space between tires and well
Build a grille block
Belly Pan
Resonator delete
Cut out spare wheel well and rivet in a piece of polycarbonate
Install lightweight racing battery
Install lightweight racing seats
Wire electric radiator fan into AC button
Wire low/high beams, turn signal bulbs and fog lights to all come on when high beams are selected
Transmission fluid change
CV axles need replaced. They click when turning (The lack of grease is probably causing drag on the drivetrain).

I will be doing a complete dash removal so there will only be minimal wiring, a full width metal support and the steering column. No gauges, I'll be using a bluetooth dongle to view RPM, Engine temps, Speed, etc. Only issue will be the fuel level since the passat doesn't support fuel level through OBD dongles :/

Fortunately, I am able to modify my ECU's fuel mapping, turbo boost and timing via laptop so I can fine tune the engine for MPG.

Lots to come!

freebeard · 05-31-2016, 12:16 PM

Quote:

Coilovers to get rid of the space between tires and well

??? In front or back?

Weight reduction will help city mileage where your aspirations are lower. Are you going to do any aero mods to help the highway mileage?

dfeldt91 · 06-01-2016, 01:58 AM

Quote:

Originally Posted by freebeard

??? In front or back?

Weight reduction will help city mileage where your aspirations are lower. Are you going to do any aero mods to help the highway mileage?

I'll be using coilovers in front and back.

I have many aero mods planned:
Grille block
Under tray
Already swapped front end for the tighter seams of the B5.5 models
Removed the antenna
Remove passenger wiper
Remove mirrors
And some other stuff...

So much work has been done recently.

cRiPpLe_rOoStEr · 06-02-2016, 01:10 PM

Would you eventually consider some engine tuning too?

dfeldt91 · 06-02-2016, 02:56 PM

Quote:

Originally Posted by cRiPpLe_rOoStEr

Would you eventually consider some engine tuning too?

I will be tuning the engine myself for economy. I have various software at my disposal to change timing, fuel mapping, boost control, etc. I got about 4 mpg more on highway when I tuned for economy in the past. Not much power at low rpms.

I've really been enjoying the car the past few days now that it is hundreds of pounds lighter. Before the car would hesitate then take off, now it is an instant launch when I want to go. I got a spot weld removal bit and will be going at the car for a few hundred more pounds.

The trunk floor is coming out to be replaced with thin plastic or lexan, rear windows are going to be lexan, I'll be cutting away the extra metal on the inside of the doors, muffler is being cut off, I'll likely get a 5 gallon fuel cell to replace the 16.5 gallon fuel tank.

Lots of work to do...

Ecky · 06-02-2016, 03:24 PM

Sounds ambitious, and I'd love to see pictures, but I'd like to ask - why not start with an already light car? You can pick up an Insight for probably about what the Jetta is worth pre-gutted, and it will be good for 70-90mpg easily without any modifications. If you're feeling really ambitious, you could swap in a diesel drivetrain and strip it too, and probably get in under 1600lbs without fuel or driver. It's probably also more aerodynamic from the factory than you're likely to achieve with the Jetta even after modifications.

freebeard · 06-02-2016, 07:08 PM

When you're going wild with the spot weld remover, keep in mind that body panels, like the trunk floor may be structural, for crumple zones if not torsional stiffness. If the body twists, the suspension can't do it's work.

True story: I saw a low-rider Impala on the freeway once that had the whole trunk (probably full of batteries and pumps) had failed right at the rear axle line so the bumper was about 8" lower than where it used to be.

cRiPpLe_rOoStEr · 06-02-2016, 07:30 PM

Sure you must be careful while cutting body panels, but even if you would need to weld some reinforcements into strategic parts you can still manage to make them lighter than the stock sheetmetal removed.