What am doing wrong? low mileage!

[grimlock]

The last few fill-ups I've been calculating my mileage. I'm only getting ~7.0L/100km or roughly 33mpg according to the calculator/converter on this website... Great compared to gas, but pretty sh*tty compared to most of the TDI's on this site...

I've vented the fill-ups, air filter is two months old (paper, NOT K&N), descreened, de-snorkelled, Stock 15" wheel size, Konig Helium lightweight wheels, mufflerectonomy (both muffler & resonator). Barely anything in the trunk, besides a truck subwoofer box & amp ~35lbs. Air tire pressure, pretty much near max for Yokohama T4, 33 PSI cold pressure (max is 35 PSI)

I have the 0.205 injectors in, with IQ setting at roughly 3.0, a little smoke.

Mostly city driving, ~10% highway, with occasional heavy-foot acceleration, but not often.

Only other thing is the intake hasn't been cleaned, but I posted about that awhile ago, and most people "guessed" that it shouldn't be an issue for me... My Passat has about ~116,000 Kms on it now...

What gives? How come my mileage bites? What are you guys getting on your A3/B4 TDI w/ city driving?

Richard

 

[Rammstein]

I almost never drive in the city/traffic.

But I can see how it goes up.

My last tank was a good mix of city and highway.

I'd say 25% city and the rest highway.

It yield me 4.9 l/100km...not too shabby...

I don't drive the hell out of the car when in the city.

As soon as I see brake lights, I don't touch the diesel pedal.

I let the car coast in gear, no fuel used.

What about your timing?

I bet it's retarded...

Mine is slightly advanced at 64 on the graph.

Check this out Richard.

How do you drive the car? Could you describe?

 

[grimlock]

Actually my timing is "dead on" according to vag-com.

I adjusted it a few months back... btw, pushing a ~3,000lbs Passat in 5th gear (by yourself) on gravel road w/ minor potholes isn't fun -- to get the cam sprocket gear thingy lined up to access two of the bolts for the injection pump!

anyway, back to the topic -- I suppose the city driving plus my "young" driving habits is killing my fuel effiency...

Anyone else with their mileage numbers for A3/B4 w/ city driving?

Richard

 

[Toronto_Vento]

33 IS really low. Not that it isn't unheard of, but still. I have a mix of city and highway driving. I would say more of it being on the highway side of things. Maybe something like 60% highway, 40% city or something. Maybe a tad bit more highway. Anyhow, I consistently have had 49mpg in the past. I upgraded injectors with someone else's (to try) and got 53 mpg on a trip to Boston for the fest. I put in brand new injectors/nozzles, and now that they are breaking in, I am figuring this new tank will get something like 51-52 mpgs...but too early in the tank to say.

What are your tire pressures set at? What speeds do you normally drive at on the highway? How about city driving? Do you take off from stops, or do you just ease away? I wouldn't say I drive like a grandparent, but I am in no way a fast driver...rather conservative (unless I get a bit of a speed bug). As Rammstein stated, coasting in 5th helps to get the mileage up a little...but I would say that only accounts for something like 2% of my distance travelled on my tank.

When you did your timing, did you do it while the engine was completely warmed up, or cold? How are your injector balancing? (I think it is block 13 or 14 in vag-com) It'll display the timing for three injectors as it relates all the injectors to injector #3. My timing is between the middle mark, and the upper limit in the graph. My timing was previously retarded, but after the change, I can't say I saw a big difference.

Do you have any boost issues, etc? How bad is your smoke, and how often do you smoke? If you smoke a lot, that is just a lot of unburnt fuel going out your tailpipe. If you leave a big cloud, that is A LOT of fuel just being pushed out the pipe. I have my IQ set at 5.0 and I only get a minimal haze at WOT. Sure, the power might be down a little compared to if I had set things to 3.0....but I have a very low tolerance to smoke. The only other thing I can think of is checking your intake manifold for clogging. I have been lucky, and haven't needed to clean anything out, but you may not end up being so lucky.

Last thing...how are your trips? Long? Short? If you have a lot of shorter trips, this'll really hurt your mileage. I have a commute of 30 km one-way to work, so my car gets nice and warm and gets some highway time.

 

[grimlock]

Hey Toronto,

My tire pressure is roughly set at 33 PSI (cold), as stated in my original post

35 is max for Yoko T4 205/50/15

Yup, I checked the timing with engine fully warmed up, vag-com warns that the engine isn't warm etc... I rechecked a few weeks after I completed the timing and still "dead on"

I haven't checked the balance between injectors (never knew that I could do that, thanks!)

As for my driving, hmmm, I would say 50-50 on the "agressive" driving. Sometimes I rocket away from the light--usually when I'm in a rush to work -- most other times I drive with normal acceleration...

I'll dial down my IQ (or raise it as much as I can) and see if that helps. Smoke isn't too bad, not a huge cloud, but definitely some extra smoke compared to stock.

Hard to see if my intake needs cleaning -- I looked down the EGR part from the upper intake piping (I think that's the part) and didn't look to bad, probably fit a golf ball in there. Mind you I fairly certain the last owner never cleaned the intake, dealership doesn't have a record of it being cleaned, either...

Lastly, my driving is relatively short trips (yikes, is it that bad for my car/fuel efficiency) 18km to work, ~8km to gym after work, another ~8-9km home.... Weekends vary a lot, short trips plus long trips.... Overall ~10% to ~15% highway driving the rest city drving.

Anymore thoughts? I plan to clean my intake next year -- I'm not really "ready" to take on that task just yet...

thanks for your help.

Richard

 

[Rammstein]

As for my driving, hmmm, I would say 50-50 on the "agressive" driving. Sometimes I rocket away from the light--usually when I'm in a rush to work -- most other times I drive with normal acceleration...

Lastly, my driving is relatively short trips (yikes, is it that bad for my car/fuel efficiency) 18km to work, ~8km to gym after work, another ~8-9km home.... Weekends vary a lot, short trips plus long trips.... Overall ~10% to ~15% highway driving the rest city drving.

Here you go, these 2 things plus the cloged intake will get you 33 mpg.

Have you cleaned the snowscreen recently?

What about the air filter?

 

[Toronto_Vento]

Unfortunately using the power of the upgraded components on relatively short trips does hurt the mileage of the car. I still think you are really low in comparison to what you should be getting, but all things considered, if your intake would be okay, I would think you should be getting in the high 30s to low 40s. That isn't unheard of with upgraded and untuned A3s with people that use the upgraded power. It seems Rammstein and I have done some work to get our systems working a little better, plus we take it easy on the roads (but I still can't drive at the grandpa speeds he does....j/k!). There is no reason that you can't get better mileage with larger injectors, as long as you aren't smoking too much, and you don't hammer the accelerator a lot. (then again some would argue why upgrade if you don't use it)

 

[grimlock]

As for my driving, hmmm, I would say 50-50 on the "agressive" driving. Sometimes I rocket away from the light--usually when I'm in a rush to work -- most other times I drive with normal acceleration...

Lastly, my driving is relatively short trips (yikes, is it that bad for my car/fuel efficiency) 18km to work, ~8km to gym after work, another ~8-9km home.... Weekends vary a lot, short trips plus long trips.... Overall ~10% to ~15% highway driving the rest city drving.

Here you go, these 2 things plus the cloged intake will get you 33 mpg.

Have you cleaned the snowscreen recently?

What about the air filter?

thanks guys!

No snowscreen!

removed long time ago

Air filter is about two months old, I managed to be an idiot and mangle the stock air filter when putting the cover back on... This was when I was working on the mechanical injection timing.... So I had to get another air filter. As we all know that replacing the stock air filter on B4 is really easy & accessible!

Yeah, I knew the mileage was on the low side, I didn't think the injectors would kill me that bad. I also used some electrical components during this calculations -- fan, and rear defrost. Fan wouldn't do much, but the defrost can be a drainer, especially on short trips. In all defense of my aggressive driving -- "driving it, like I stole it" - to help prevent clogging

I plan on cleaning the intake manifold next summer.... Don't have time and a garage to do it in now.

 

[trae]

Hi Grimlock,

For comparison purposes I have two B4 Passats, one sedan Upsoluted, one wagon with PP520 injectors and a 2 1/2 inch straight pipe. The timing is set properly on both.

The sedan typically gets mid 30's in mixed City driving; its my wife's car and despite best efforts tire pressures frequently get really low.

The wagon gets around 40 driven reasonably and prudently. I consider reasonably and prudently averaging about 80. The last few highway trips the mileage has been lower but the speed has been, well, significantly higher.

Even pulling a fully loaded U-Haul trailer, fully loaded with 4 bodies, a ton of camping equipment, and a rack with four bikes on top, the wagon manages to average about 25mpg at 80+ mph.

I have wider low profile tires on the wagon during the fair weather months; it does slightly better with the stock tires back on in the winter. Either way I maintain 45psi.

Driving style definitely plays a role in mileage; I used to have a MB300TD wagon which the previous owner said got 28mpg on the highway; I got around 25 but admittedly drove the snot out of it. Still beats a gasser.

Wife's car probably needs new injectors at 120k and I have been meaning to clean both intakes and intercoolers since I got the vehicles.

Regards, T. Rae