Sometime on Friday night, after about three hours of enjoying the low-end torque and super-smooth dual-clutch DSG transmission of our 2009 Jetta TDI, I looked down at the fuel gauge and saw that, despite the trip odometer registering 160 miles, the needle wasn't even at the 3/4 tank mark. Now clearly I had done some damage to the overall fuel economy of this tank after only a few dozen miles, but still, the nifty little trip computer was registering almost 30mpg. That's pretty good, I thought. But surely I could do better, much better, if I really set my mind to it.
I drove immediately to the nearest gas station with available diesel and filled up the tank. I filled it very, very slowly (diesel tends to foam if poured too quickly which can cause a premature nozzle click-off) and then waited for the fuel to settle itself and, as slowly as the pump would allow, topped it off. The '09 Jetta took 5.717 gallons after only 163.9 miles. Clearly someone else had been enjoying the torque, too.
While you may be familiar with the diesel Jetta's impressive fuel economy, you may not be so familiar with my less-than-stellar EPA rating: I'm from the East coast. I'm always in a rush. I live in the city and rarely stray onto anything resembling a freeway. This test was going to be a test of the Jetta as much as it was of my will power.
Easy on the throttle. Stay way away from the brakes. Keep moving at all costs. A/C off. Tom Gabel in the CD player-- if my lethargic pace caused my boilers to overpressurize, I wanted to have something I could scream along to while keeping my right foot rock-steady.
A/C off was the first rule broken. It was something like 85 on Saturday. That's too hot. A/C on for a good portion of the afternoon.
Easy on the throttle was next to go. That same day it seemed like every person on the road washed down their morning coffee with a handful of Xanax. How so many indifferent, directionless people could converge on the same roadways at the same time was beyond me. Only a healthy dose of throttle-- after 3 tracks of solid screaming-- could fix the problem. What can I say? I wasn't built to be a hypermiler. Or to sit idle when I could advance my position.
Other than that, though, I was perfect. I timed the lights as best I could; coasted as much as was safely possible; accelerated on pace with most school busses and generally just tried to be as steady and smooth as traffic and safety would allow. ( I refused to be that guy going 50 in a 65 just to get 2mpg better economy.)
After just over two days of careful driving, and a very careful refueling early Monday from the same pump I started with Friday night, these were the results:
Total city miles: 98.7
Total highway miles: 54.6
Total miles: 150.2
Total Gallons: 3.562
Average MPG: 43.037
Looks like there might be something to this driving frugally thing after all. Now if only it were possible to do without screaming my vocal chords raw from the stress and boredom of hypermiling.
Mike Magrath, Vehicle Testing Assistant @ 12,910 miles
louiswei says:
08:01 PM, 03/30/09
Toyota Prius will give you 66 mpg under "careful driving"...
http://lexusnet.com/forums/index.php?topic=124.0
wizard8873 says:
05:27 AM, 03/31/09
85 and too hot for A/C? wow. here in chicago, it gets up to the mid 90's and high humidity and I rarely use the A/C. actually, i only turn it on when other people are in the car. hate A/C in the car. drive a bit and you get used to the heat so it's not a shock when you step out.
i was able to pull 33mpg in my V6 altima last summer with careful driving. got about 21mpg normally with my driving. i don't know, if i was to decide between a boring, fuel-efficient car and something fun but gas guzzling, i'd rather go with the fun car.
seppoboy says:
06:08 AM, 03/31/09
Mike, not to be picky or anything, but a diesel vehicle does not have a throttle, diesel engines are run unthrottled. The right pedal is an accelerator, it is attached to a control of the fuel pump volume of output. The throttle in a gasoline-engined vehicle controls air flow, not directly on fuel flow.
It's easy to fall into habits and vocabulary derived from gasoline-engined vehicles, but it's inaccurate at the margin and sometimes in a fundamental way. Clear language and clear thinking support each other.
And understanding how the vehicle's drivetrain actually functions aids in getting the best performance, fuel efficiency, and other fun stuff.
Diesel drivers never stop for gas, they stop for fuel. Vive la difference!
warren_w says:
08:10 AM, 03/31/09
@louiswei
By careful driving do you mean, concentrating really hard on not driving the thing into a ditch or a tree because it is so boring? I wish they would just put automatic driver control on the next gen Prius so I could sit back and take a nap while in one. There's nothing interesting about it except the time until I get out.
As Mike Magrath said of the 2010 Prius "...the closest we're going to get to private, driverless capsules that transport us anywhere we want. There's no driving involved."
If you only want high mpg get a Prius. If you want something that's fun with good mpg get a diesel BMW, Mercedes or VW.
carfreak8394 says:
02:20 PM, 03/31/09
"85 and too hot for A/C? wow. here in chicago, it gets up to the mid 90's and high humidity and I rarely use the A/C. actually, i only turn it on when other people are in the car. hate A/C in the car. drive a bit and you get used to the heat so it's not a shock when you step out."
It's 85 right now here in Florida, and there's no freakin' way I'd drive in a car without air. Way too hot. But I hate the heat, so..
"If you only want high mpg get a Prius. If you want something that's fun with good mpg get a diesel BMW, Mercedes or VW."
warren, you're right, but not everyone can afford a $45,000 BMW 335d (although it is one nice car). Now that I think about it, I guess just could just get a Jetta TDI, but still..
redliner says:
08:11 AM, 04/ 1/09
A co-worker bought one of these a few months ago. It's white, loaded with every option, and stick shift. He gets about 40mpg without even trying. The manual is definitely more economical both in initial purchase price and in fuel economy.
boxermike says:
11:26 AM, 04/ 1/09
louiswei:
No, I don't think you would get 66mpg in a new Prius with just careful driving-- and certainly not with the "loop" I did. That number you linked to was on a specially designed 33.8-mile fuel economy loop-- no highway. The same one we wrote about over on Green Car Advisor here: http://blogs.edmunds.com/greencaradvisor/2009/03/testing-the-2010-toyota-prius-we-enter-fuel-economy-run-tarnish-a-reputation.html
In a back-to-back real-world fuel economy loop with the 2010 Toyota Insight, we averaged 52.2. Better than the Jetta, still, but with the diesel you don't have to worry about battery disposal.
seppoboy,
Well done, but in the words of Fishy Joe GIllman, "good point, not interested." While we're on the topic, though, in order for the casual person to switch teams and bat for the oil-burning team it would probably be helpful for such terms to fade away. People won't want to learn new terms, most barely know the ones they're already supposed to be familiar with.
-mike
fuguf1sh says:
04:35 AM, 04/30/09
Thanks for posting this. I always look for real world MPG numbers. Automag reviews have their place, but as in the case of the 2010 Prius/Insight, they were carefully controlled test drives on predefined courses.
I'll definitely keep the Jetta TDI in mind when it comes time to replace my commuter. A hybrid's energy savings profile does not lend itself to my daily 100 mile 100% highway commute. I'd rather have something that sips fuel at 65 mph but still has 200+ lb./ft or torque on demand.
loki1098 says:
11:25 AM, 05/19/09
The Prius' and hybrid Civics I see everyday certainly aren't getting 50+ mpg. Those are the guys driving 80+ mph on the HOV lanes and being a general nuisance. I bought the TDI wagon last month for commuting duty and easily get 40-42 mpg. 95% of my driving is on the highway and the TDI is a better choice.
jbaustian says:
12:40 PM, 05/21/09
You wrote: "I filled it very, very slowly (diesel tends to foam if poured too quickly which can cause a premature nozzle click-off) and then waited for the fuel to settle itself and, as slowly as the pump would allow, topped it off. The '09 Jetta took 5.717 gallons after only 163.9 miles. Clearly someone else had been enjoying the torque, too."
What happened is that the previous driver did not top up the tank like you did. (TDI owners call it "venting"). Careful fueling can allow you to add up to two additional gallons, and can extend the range between fill-ups by another 70-100 miles.
vxla says:
11:07 AM, 06/22/09
Why didn't the S edition (2009) get an MPG meter? I love my '09 S, but seriously...give me a damn MPG meter!