Googled hypermiling...found myself here ('17 Jetta 1.4T auto)
 

I've been trying to eek out as many MPGs as possible lately and I'd heard the term hypermiling so I typed it in Google and, well, here I am. I have a 2017 Jetta with the 1.4t and an automatic trans. I'm looking forward to learning the best ways to reduce fuel consumption. Does anyone know the most efficient engine RPM when cruising in 6th gear....or any particular gear for that matter? Thanks!

Depends on the engine and transmission.

With the VW diesels, you sometimes do a little better if the engine is in the boost rather than just off-idle, but I'm not quite sure if that extends to their gasoline turbos.

Experimentation is definitely in order.

As far ad I know, lowest RPM with turbo fully active. With diesels its around 2200 rpm, but you need to find yourself. Try to search for kW vs RPM charts, o;-)r torque vs RPM. You can usually tell where the boost is active.
And get either OBD2 adaptor and Torque app, or ScanGauge or UltraGauge or similar device. Ot will tell you more.

Oh, I almost forgot: Welcome to the forum! :)

Thanks, Niky. I included the engine & transmission info but I guess I should have been more specific in saying I wanted an answer that applied specifically to my car. I've been experimenting but I asked because I thought there might be a chance someone would be able to share some definitive info. Also, the Jetta does not include a gauge or any other mechanism to inform you that it is using boost.

It’s not stunt driving, it’s
Records.

Cut the annual miles is
First

Drive the remaining fewer miles (having accomplished same ends) at a higher level of
Skill

Which is pretty much Never Stop & Never Idle

The key to it all is
Discipline

Tally annual miles & all fuel purchased. Plan all trips. No cold starts. Combined errands. Best routing.

Against Average Miles per
HOUR

Raise that number by 20% and you’ll see
Savings

.

Thank you!

I had thought that being under boost decreases efficiency. Thanks for that info. I'll have to search for some charts.

Yup, all common sense stuff.

Do you know where I can look to find info for the most efficient engine RPM when cruising in 6th gear of my particular car?

The rewiew I was able to find says 100 km/ h, 2500 rpm, 5.7 l/100 km. But it is 6 speed manual. All (around 400?) jettas in my country are probably manual.

Buy bluetooth OBD2 dongle. Its about $6. Put it in your OBD port, pair itwith your smartphone. Download Torque pro app ($4). Enjoy instant MPG and more. Find what suits you best.

Btw the rewiew says peak torque from 1500 to 4000 rpm, so keep in this band.

In a gasoline powered engine.
Diesel engines want more air.

Thanks for clarifying. So, to be sure..
Gas engine under boost = bad (inefficient)
Diesel engine under boost = good (efficient)

?

The diesel engine wants some boost to be most efficient.
That way you have plenty of air to burn a little bit of fuel.
When I added the turbo on by diesel suburban I picked up at least 10% more fuel efficiency with out changing anything else.

If a gasoline engine is running boost then the engine is producing more power than it would at wide open throttle with no turbo.

Driving a rented 1.2L TSI Golf in Finland a few years ago, I noticed the instantaneous MPG on the factory instrumentation was the same no matter how I accelerated. So I used wide-open throttle to spend less time accelerating.

On some cars the display maxes out. Ie my Fiat maxes out at 25l/100km, even though in the lower gears at least it's quite capable of using more.

Not for your specific car, but almost every car I've ever driven (gasoline) gets its best fuel economy at the lowest engine RPM you can reasonably drive in top gear. That's a good rule of thumb to follow.

For many examples, see:

Thread: Speed vs. MPG charts (post 'em if you got 'em)

Also, I second the recommendation of picking up some additional MPG instrumentation. You ideally want to see both instantaneous and trip average.

Another thing to pursue: if your automatic transmission has a "manual" mode, you can probably request earlier upshifts than the default "D" mode, and get into higher (fuel-saving) gears sooner.

EG., related topic:

Thread: "Short-shifting" a Jeep Patriot & Audi A4 CVT (forcing early "upshift") saves gas

And... belated welcome to the forum!