Just bought 2015 Jetta TDI. MPG is lacking

Miss_Athanatos

Veteran Member
Joined
Oct 21, 2015
Location
Kansas
TDI
2015 Golf SportWagen 6-speed manual; 2016 3500 Ram Tradesman 4X4 6.7L Cummins 6-Speed manual
No Phase 1 "fix": I filled up my tank and left home at 10:00 AM yesterday and did about 8 hours of driving (round trip) together with 8 shutdowns/startups at rest stops and historical sites. I did five 3 minute idle cool downs before 5 of the shutdowns after working the turbo hard. I drove probably 1 hour on very hilly and washed dirt roads, some places were only passable in 1st gear. During that time, I didn't get above 15 MPH. The rest of the time was split between gravel and paved roads driving between 20 and 65 MPH. I traversed a total of 343 miles and used approximately 6 gal. of diesel. The estimated range left was 345 miles. Calculated, that's approximately 57.2 MPG for my trip yesterday.



This is the typical performance that I see for my vehicle. General driving style: high gear, low RPM.

-- Nicole
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Jetta_Pilot

Top Post Dawg
Joined
Apr 14, 2005
Location
West Hill, Ont. Nov.2nd in Mexico till April 27th
TDI
2015 Passat Highline TDI Candy White (SEL Premium) long gone 2002 Jetta TDI
The only way to get accurate Mpg is to fill the tank up to the top each and every time. Keep track of the mileage when filled and amount of fuel put in and do that over many fill-ups, i.e 1 or 2 years. That is the ONLY way to get a true average Mpg. Any electronics readout such as MFD lie to you!!!!!
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Actually if you record over a large number of tanks it doesn't matter if you fill it completely or not. If you're looking for a one or two tank average it does.
 

RIP TDI

Top Post Dawg
Joined
Feb 16, 2000
Location
Santa Barbara, CA
TDI
'15 GSW SE 6MT, '01 Golf GLS 5MT, '96 Passat variant
Any electronics readout such as MFD lie to you!!!!!
Although the FE on these cars is very good, take those readings with a big grain of salt. The cluster in my car reads at least 4 MPG high. Others have reported similar errors.
I have been driving my DSG Sportwagen In Central Ohio from Buckeye Lake to Gahanna daily and since april ove rthe last 11k miles I have averaged 43.6 mpg according to Fuelly, my MFA reads consistently 4-5mpg high since fillup and I assume since start.
You all know that MFA calibration is a simple VCDS adaption, right?

Instruments (17)/Adaption/00499

A value of 108% (100 is default) seems to work well for some. My recorded deviation from all tanks is about that, so I used it but just made the change and so cannot comment yet on accuracy.

I should qualify that this is true at least for MkVII Golfs.
 
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Scoutx

Veteran Member
Joined
Jun 4, 2012
Location
Virginia
TDI
2012 Jetta (6MT) - 1000 Mile Club (retired)___ 2015 Jetta SEL (6MT)
My readings are averaged over city and highway driving.

In my opinion there are a lot of dreamers around here.:eek:
In my 2012, the lifetime average was 48.3mpg under all conditions over 188K. So I was regularly running in the +50mpg range.

My newer 2015 is currently running an average of about 51.2 mpg with about 5K on the clock.

Further I have proven that with luck and ideal conditions mpg above 60mpg can be maintained in a Mk6.

Only known Mk6 in the 1,000 mile club.

While the car has the capability, the governing factor is still primarily your right foot and how well you can control it.

That said, a DSG is going to cost you about 2 mpg.
 

jessej

Member
Joined
May 14, 2014
Location
Indiana
TDI
2013 Jetta TDI
2013 Jetta TDI, mileage runs between 40 and 45. I have yet to get over that. I'd like to know what effect the new government emission mods have had on TDIs. I do experience improved mileage when I dump a can of Sea Foam or GumOut fuel treatment into the tank. Summer AC driving on interstate at 75 nets me about 41. If anyone knows about those computer chips in TDIs which are supposed to improve mileage and performance, I'd like to hear about it. Good Luck, Cowboy CVW
 
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