Which US spec TDI with a few mods achieves the greatest MPG typically?

[Meek]

Thanks for your help.

fwiw my uneducated guess is 98 Jetta TDI

 

[TurboABA]

Under what use pattern?

 

[Meek]

Roughly maybe:
40% city,
55% 45mph with a possible stop (red light/stop sign) every 3-8min,
5% 70mph highway
And a light foot

 

[Johhny04]

I would say any platform that has an ALH engine.

 

[TurboABA]

Any MKIII will be lighter and could inexpensively be 5th gear swapped for the 70mph use.... but because you also do a lot of city and 45mph, I'd want something with a 6psd in order to have a better spread...... the problem with looking at newer gens is all the weight you're gaining and all the deletes you need to perform depending on how "new" you go to gain MPGs....... but at the same time, the newer stuff has less drag, so I'd be a tough call.
Budget and available options are also a huge factor, as if you can get one gen over another at a significant cost savings, a slight MPG advantage is nullified.

IIRC the Passat B5 Wagons had some really nice cd... something like .27 or something...... but those won't be easy to come across and mods won't be "few" to achieve the possible MPGs.

 

[Mbmaring]

Had a 99 jetta tdi 5 speed we could get 50 fairly easily

 

[coolusername]

Any MKIII will be lighter and could inexpensively be 5th gear swapped for the 70mph use.... but because you also do a lot of city and 45mph, I'd want something with a 6psd in order to have a better spread...... the problem with looking at newer gens is all the weight you're gaining and all the deletes you need to perform depending on how "new" you go to gain MPGs....... but at the same time, the newer stuff has less drag, so I'd be a tough call.
Budget and available options are also a huge factor, as if you can get one gen over another at a significant cost savings, a slight MPG advantage is nullified.

IIRC the Passat B5 Wagons had some really nice cd... something like .27 or something...... but those won't be easy to come across and mods won't be "few" to achieve the possible MPGs.

The Mk7s get excellent MPGs out the gate, no deletes necessary.

 

[Andyinchville1]

I'm thinking a MK 2 jetta (light weight) mated to an ALH engine and 6 speed tranny would be the best combo .... even better if you could mod the bodywork from 4 door sedan to a wagon for more space.

Andrew

 

[coolusername]

I'm thinking a MK 2 jetta (light weight) mated to an ALH engine and 6 speed tranny would be the best combo .... even better if you could mod the bodywork from 4 door sedan to a wagon for more space.

Andrew

I feel like a whole-ass engine swap doesn't really qualify for "a few mods."

 

[TurboABA]

The Mk7s get excellent MPGs out the gate, no deletes necessary.

It all comes down to expectations... my beloved '10 got 5.5L/100km over it's nearly 300k km lifetime, it was fully stock, used year round, rolled on 16s in winter, 19s in summer, all DPF and emissions stuff there, not hypermiled, etc..... if the expectation is to get high FE, deletes and better driving is necessary on the newer gens for sure.

 

[IndigoBlueWagon]

ALHs do well, but a B4 will, too. My B4 was owned by BRUSSELS BELGIUM here and he regularly got 57 MPG running at 58 MPH. That would make me crazy, but it is impressive. Lug_Nut here got a high of 83 MPG on biodiesel on a B4 Wagon during a FE run. He was using all kinds of tricks to get that, however.

 

[turbodieseldyke]

You don't need a 6sp at 45mph. Pedal work will determine your mpg more than your engine, with the speeds and parameters you laid out. Coast as long as you can to the stop signs and red lights (without pissing off cars behind you).

 

[Prince]

My 2015 Golf Sportwagon will get under 4.0 l/100km at 100 kph which is more than 58 mpg.

Hard to be consistent with wind, inclines, etc

Going slower it will be less than 3 l/100

 

[TurboABA]

You Sir, are delusional.
That is all.

 

[Prince]

You Sir, are delusional.
That is all.

No, I know how to read the consumption gauge. You should try it.

 

[lemoncurd]

You Sir, are delusional.
That is all.

he isnt... the mk7's are simply that good. do some research about soot and nOX output.

you'll notice theyre inversely proportional! and also notice how the mk7's spray DEF?
yeah, thats the stuff that chemically deals with nOX. therefor, the mk7's are programmed to have a cleaner burn, less soot! and more nOX, which results in much higher MPG's!

 

[coolusername]

he isnt... the mk7's are simply that good. do some research about soot and nOX output.

you'll notice theyre inversely proportional! and also notice how the mk7's spray DEF?
yeah, thats the stuff that chemically deals with nOX. therefor, the mk7's are programmed to have a cleaner burn, less soot! and more nOX, which results in much higher MPG's!

Yep, that's why I mentioned them. They're excellent, and the reliability is much better than the Mk6s. Shame they were only sold for a year before Dieselgate hit.

 

[Lightflyer1]

No, I know how to read the consumption gauge. You should try it.

If you are reading the gauge then it is probably wrong. Around here we pay attention to full tanks calculated by gallons consumed and miles traveled. Multiple tanks is also preferred. Anyone can say their gauge said this. The gauge can also be manipulated by different driving techniques. Gallons and miles can't, especially over the long run.

I have tracked every tank since new in my Fuelly. I can pretty much guarantee you that my car will get at least 34 mpg average.

 

[Darth_Furious]

If you are reading the gauge then it is probably wrong. Around here we pay attention to full tanks calculated by gallons consumed and miles traveled. Multiple tanks is also preferred. Anyone can say their gauge said this. The gauge can also be manipulated by different driving techniques. Gallons and miles can't, especially over the long run.

I have tracked every tank since new in my Fuelly. I can pretty much guarantee you that my car will get at least 34 mpg average.

I can confirm that. The gauge says 50ish mpg since last refuel. Fuelly (and by hand) is usually 10-12% less. I get like 45-46mpg in real life. Sometimes it's super easy to tell. I get like 470 miles on the trip meter since last fuel up, I put in like 10.2 gallons so I know it's a little under 47mpg instead of the 53mpg on the gauge.

 

[Darth_Furious]

You Sir, are delusional.
That is all.

He is claiming 58mpg going 62mph (conversion done by me). If the dash says 58mpg, then from my experience I would probably get 52 or 53mpg if calculated by hand. Going 62mph on a flat road with ideal situations, I have done 56mpg 100% highway with no stops until fill up (hand calculated - 400 miles a little over 7 gallons).

I get over 64mpg (hand calc) when I drive 45-47mph at 1am when there are no other cars (just as an experiment to see what I could do). Painfully slow driving - don't recommend it

 

[Darth_Furious]

I would say any platform that has an ALH engine.

The ALH cars are light and get great MPGs, but the mk7s feel so much more powerful. If you drive lightly and don't tap into the power, you can still get great MPGs, but when you need that power, the mk7 is much better (and it doesn't even drag down your MPGs if you use it sparingly/when needed)

 

[hskrdu]

No, I know how to read the consumption gauge. You should try it.

Calibrate your fuel consumption via VCDS based on full-tank pen and paper calculations (over several tanks, as Lightflyer said) and don't pay attention to your "instantaneous" readout, and then reading your consumption gauge will have more real-world value. (And snarky replies aren't quite a helpful as asking why a member might suggest your consumption values are questionable- at least without context).

Regardless of DEF, the Mk7 certainly, on average, does not get better FE than a Mk4. We also have a Mk7 that will indicate terrific MPG numbers, for short (less than a tank) under ideal conditions. Unfortunately, the hand calculated translation of 60MPG (in one Mk7) is closer to 51, and it doesn't impact the OP's question much, unless the new question is "What is the best fuel economy you can achieve, under ideal conditions, and over a single tank or less?" The Mk7's are great, but millions of miles recorded at Fred's (and elsewhere) reveal the Mk4 will typically achieve higher FE than the Mk7, and outliers with unique driving conditions, or using condensed mile averages, don't really speak to the OP's question.

 

[IndigoBlueWagon]

My modded MKIV is quicker than my tuned MK7 and also gets better FE, although I've seen some pretty impressive numbers from the MK7 lately. Last tank was over 50 MPG.

 

[Lightflyer1]

In my 2013 Passat tdi on the open highway at 65 mph it would get just over 50mpg. The Beetle doesn't come anywhere near that car. But the Beetle is a commuter car and hardly ever sees the highway for long, for the most part. Usually just the 70 mile trip for work three days a week. But I am also in Texas and doing 60mph here on the highway just isn't going to happen much. Usually speeds are 70-100mph (car speeds) on the more open highways.

 

[oilhammer]

There's too much variability to give a definitive answer to this, often depending on driving style. Also, if the backdrop to this question is how best to pinch pennies, I can tell you there are probably (almost certainly) cheaper ways to get from A to B even if they do consume a bit more fuel.

 

[Lug_Nut]

Within the conditions of the thread title (US Spec, few mods, greatest mpg) I'd say the A3 AHU Jetta is tops. That's based on a no-practice, one-time use of a borrowed car (Jetter's no mod "X" VIN 1999) for use in a fuel economy challenge put on by the AMEC. Mid-80's mpg for that event.
B4 1Z sedan next (low 80's as a best in competition, 52.5 average for my total ownership)
B4V 1Z (was converted from VR6 GLX, so 'modified'), 50 ish my ownership average
A4 AHU Jetta manual, 48 ish average
A4 BEW (PD) Jetta wagon, 45 average lifetime
A3 AHU (modified to ASZ 130 hp) Golf manual, 40-ish
B5.5 BHW Passat wagon auto, high 30's.

I don't recall what my A3 Cabrio AHU (was ABA 2.0) was other than mid-40's

The DRIVER is the more important factor. A B4 driver complained that his car was terrible because it got nowhere near the mpg of others regardless of how hard he tried. A high mpg B4 owner drove it at the Grand Rapids fest, with the low mpg owner in the car, and beat the low driver's best.

 

[kjclow]

From my experience, I could average mid to upper 40s in my 2000 beetle in daily driving. The wife had issues getting it over 40 mpg in the same driving conditions. Best I ever got was mid 50s on a single tank running to the NC coast and back on state roads in early spring with a fresh oil change. Filled when I left home and filled when I got back to Charlotte. Never went above 65 mph for the whole tank. I really have to pay close attention to push the JSW over 40. Usually run mid 30s in daily driving.

 

[IndigoBlueWagon]

I've been getting right around 50 MPG in my '02 Wagon for some time now (like, two or three years). I don't think I'm particularly careful about getting best FE: if traffic is running at 80 MPH, I go 80. I do tend to coast and use my brakes very little, however: the first set of brakes on this car lasted over 150K miles. I think being smooth and thinking ahead makes a big difference. I always look 3-4 cars ahead on the highway and lift soon enough when traffic is slowing so I rarely have to use the brakes.

I also think some TDIs do better than others.

 

[oilhammer]

Yep, any time you use the brakes, that's like taking back any motion the fuel gave you to get there. I employ the brakes very little as well, and use the fuel cut function as much as possible (leaving the car in gear). I find no matter what I do, though, I cannot get this new-to-me BEW+automatic Golf to break much over 40. It runs fantastic, but it's probably dead even with the B5 for fuel economy which seems strange, as it is smaller, lighter, and certainly has nowhere near the power.

 

[Prince]

It is amazing some of you are saying the gauge is wrong. How do you know and who the F cares?

The mileage is incredible. Stop and go is hard on fuel economy. Steady state at reasonable speed is phenomenal.

My 2015 has 150 hp and phenomenal fuel economy. It is hard to get better than that. I suppose some of you will say "no way it has 150 hp may ass-o-meter says it is only 136".