What should I expect after delete and mods?

Kobayashimaru

Member
Joined
Feb 24, 2020
Location
New Jersey
TDI
2012 Jetta Sportwagen
Greetings!

I've got a 2012 Jetta Sportwagen w/ DSG and 115,000 miles, and I'm currently in the process of doing lots of maintenance and upgrades. Before I parked it, I was getting 36 mpg on the highway at best. Previous to VW swapping out a clogged DPF, I could get 40 highway. As far as I know, all of the "dieselgate" modifications were completed prior to me owning the car.
While my car is parked, the following maintenance and modification are being done:
  • Timing belt, idlers, tensioner, water pump, serpentine belt
  • New alternator (nothing wrong with the old one. The new unit is wound for 200 amps output) and Optima DH6 battery
  • New AC compressor because the CCV was seized inside the unit. Since I've had the system open for a while, the accumulator and expansion valve are also being replaced)
  • Oil change with Mann filter and Rotella T6 5w40
  • Coolant flush with the purple Pentosin. A Frostheater is now installed
  • DSG fluid and filter (every 40k)
  • Fuel filter (every 20k)
  • Swapping the CP4 fuel pump for a CP3, which also means deleting the auxiliary pump
  • DPF, NOx cat and flap being deleted in favor of a Rawtek kit
  • All new EGT and O2 sensors
  • Turbo upgrade to Euro-spec Borg Warner CR170
  • Malone DSG tune
  • Stevenson Stage II engine tune for (supposedly) 195 bhp and 331 ft/lb of touque, compensation for the CP3 and CR170, readiness monitors set for state inspection
Assuming I'd drive the car like it was stolen by a three-toed sloth, can anybody with a similar setup give me a rough idea of what kind of numbers I may be seeing when I get the car on the road?

I know that adding horsepower traditionally reduces fuel economy, but then diesels are different. My only uncertainty is the CR170 turbo. Will a bigger turbo increase or reduce MPG?

Ultimately, I'd like to see 45 mpg highway given a steady 60-65 mph. I know that there are other variables, like vehicle weight, tire contact and rolling resistance, ground clearance, coefficient of drag, etc.

Thanks,
Joe
 

turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
45 mpg should be pretty easy at those speeds, as long as you don't have a sail on the roof. That turbo is really only marginally bigger, so shouldn't hurt FE whatsoever.
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Joe, in the gasoline world adding power will reduce fuel economy almost straight across the board.
In the Diesel world, more power doesn't always mean lower fuel economy.
With a proper tune and a light right foot, you can sip fuel yet have power when you need it.
 

Bradm

Veteran Member
Joined
Jan 26, 2019
Location
Wisconsin
TDI
02,03,05, Jetta 99.5 Golf
I lost 4 almost 5mpg when I switched to rotella T6. I thought id start running it since i was deleted. Car drove like i had a boat anchor tied to it. I went back to 507 and its great again. Consistent 50-52mpg 53.4 is my best
 

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
I lost 4 almost 5mpg when I switched to rotella T6. I thought id start running it since i was deleted. Car drove like i had a boat anchor tied to it. I went back to 507 and its great again. Consistent 50-52mpg 53.4 is my best
Good data point. I realize is one data point but thank you!
 

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
Good data point. I realize is one data point but thank you!
HI,

When you lost that many MPG with Rotella , were you using Synthetic Rotella or Conventional Rotella?

What oil did you switch back to (brand).

I am using Rotella Synthetic but would try something else if it meant better MPGs (with proper protection for the engine of course).

Thanks

Andrew

OOPS somehow did not quote the correct quote but not sure how to change it now ....
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
The short time I had a deleted 2010 Jetta sedan, with the DSG, it would easily beat 50 MPG (usually the MFA would display somewhere between 53 and 56). Mostly all highway, 70+ . Mild bump in power, very modest, which is perfectly fine and I think the DSG works fine that way. If it had the correct number of pedals I would have kept it. Because 2010 was in my opinion a good year for the sedan... got the slightly upgraded CJAA engine, but still a "Golf with a trunk", so a somewhat unique year.
 

deshet

Active member
Joined
Sep 29, 2005
Location
Virginia, Best Country on Earth USA
TDI
Not Yet
I know there are a few threads that discuss using Rotella T oil in our cars and this may have already have been covered (I searched but didn't find anything) but I E-Mailed shell expressing disappointment that Rotella T6 isn't certified for VW 507.00 and they sent me back a response that some may find interesting:

Because the formulation requirements for North American diesel
engines are considerably different than for European diesel engines
like the VW TDI, it is not possible to make one product that would
meet both sets of specifications. Therefore, our Shell Rotella T6
Full Synthetic Oil SAE 5W-40, which is intended primarily for the
North American diesel engine market, won't ever be able to meet the
VW 507 00 specification. Further, since the primary marketing
emphasis for our Shell Rotella oils is for heavy duty diesel engines,
our marketing group has generally chosen not to make products in this
line for the passenger car market.

We do, however, have products in our Pennzoil and Quaker State lines,
where the emphasis is passenger cars, for your application. Pennzoil
Ultra Euro L SAE 5W-30 and Quaker State Ultimate Durability European
L SAE 5W-30 are certified to VW 507 00.

Thank you for your interest in Shell Lubricants!

I found this in another thread. I believe that T6 is geared towards heavy duty diesel whereas the 5-30 weights diesel oil are rated for light duty diesels. The reduction in fuel mileage would make sense because of the thicker oil.

Thanks
 

NewTdi

Top Post Dawg
Joined
Jan 15, 2004
Location
NorCal
TDI
2003 Bora, Reflex Silver
I am going to jump in on the oil aspect of mileage. I recently changed (last week) from Rotella to Liquimoly 5-40 because of excessive oil consumption. I can tell you that mileage is up a smidge (2-3mpg) however most importantly I keep the tires inflated at 38psi. In the last 10K mile interval I had to add 1/2 quarts of oil (Rotella). Hopefully with Liquimoly I will not see any oil cunsumption.
 

dieseldonato

Veteran Member
Joined
Mar 10, 2023
Location
Us
TDI
2001 jetta
If your using oil, your using oil brother. The brand shouldn't matter. The slight difference in oil weight also shouldn't manifest in that sort of major fuel economy change. Most mfg of smaller output diesels spec a 5 - 10 w30 weight for cold weather performance and "adequate" summer protection. By any standards these diesels are light duty. Untill you start turning them up, now your putting higher demands on the engine, which in turn puts higher demands on the engine. We routinely switched from a 15w40 to a 5 or 10 w30 oil in smaller diesel in heavy duty and industrial settings for winter use. Kubota, yanmar, and the kdi kohlers were particularly susceptible to slow crank issues with a 15w40 oil. Even switching to a modern 5w40 made them crank much easier and we never noticed any sort of fuel economy declines.
Having said that, it will be interesting to see what my results will be after my first oil change, as I run 5w40 Rotella in all my other diesels, so I was planning on using that in the jetta. No idea what's in it currently. According to the oil change sticker I have about 1000 miles til its due. Should be enough to get 2 tanks or so of fuel through it. Although with the mods I have planned (thanks again for the tips!) Idk how telling it will be or if I'll get to another oil change before parts start getting replaced.
 

Bradm

Veteran Member
Joined
Jan 26, 2019
Location
Wisconsin
TDI
02,03,05, Jetta 99.5 Golf
Your yanmar, kubota, kohler is not a tdi, brother.
Were also talking about common rails not your alh
 

dieseldonato

Veteran Member
Joined
Mar 10, 2023
Location
Us
TDI
2001 jetta
They all make similar common rail engines of the same displacement, not to look at other similar engines for comparison to like characteristics is like saying an apple isn't an apple simply because one is red and the other is yellow. I'm also speaking with 20 years as a diesel mechanic, I may not be uniquely familiar with these specific engines, but engines of similar architecture and displacement share similar traits.
 
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