Author Topic: Fuel economy kinda sucky - intake? (Read 4819 times)

bhtooefr · « **on:** January 26, 2006, 05:54:14 am »

First, let me say that I'm not at all sure that the fuel gauge is at all accurate, nor am I sure that the estimates of how many miles I've gone are accurate (I use Streets & Trips to calculate that after the fact, as my odometer is broken). So, my estimates could be TOTALLY off, here.

Anyway, at 1/2 tank (note: I vented, and have been told that my car has a 1.6 gallon vent, for 8.6 gallons on the first "half tank" (and 7 gallons on the second "half tank")), I was at 295 miles. Doing the math, that came out to 34.3 mpUSg, which is absolutely pathetic, especially considering that it's an 80% highway tank, and much of that highway was at 55 MPH, not 65.

There's very little smoke, unless I want there to be. It's not LACKING for power - considering it's an NA diesel, anyway...

Now, here's the trick. You know that hose that goes from the air filter to the thing on the passenger side of the car, for the intake? Mine isn't there. I'm sucking in air that's right next to the hot engine. Would either restoring that hose, or going straight to cold air induction help me at all?

bhtooefr · « **Reply #1 on:** January 26, 2006, 07:32:16 am »

It's got air filtration, FWIW. Basically, the tube that goes from the "intake" thingy on the side of the car to the air filter is gone.

However, the air is introduced into the car via the air filter.

BlackTieTD · « **Reply #2 on:** January 26, 2006, 08:56:33 am »

Quote from: "bhtooefr"

Would either restoring that hose, or going straight to cold air induction help me at all?

maybe, marginal.

i'd look into service items like air filter, wheel bearings, alignment, tires... are those all A-OK?

HP · « **Reply #3 on:** January 26, 2006, 09:34:55 am »

Just by the way, what are the prices of diesel and gasoline in the US and in Canada (I know it varies from state to state...) :?:
In Portugal, regular diesel is €1.03/liter (= $4.73US/gallon) and 98 octanes gasoline is €1.32/liter (= $5.98US/gallon). These are the current inflated prices! :x

BlackTieTD · « **Reply #4 on:** January 26, 2006, 09:38:34 am »

i've been paying around 90 cents a litre. thats canadian. filled with sunoco gold a few weeks ago, i think that was a hair over a dollar.

zyewdall · « **Reply #5 on:** January 26, 2006, 10:22:08 am »

Last I looked diesel was US$2.65/gal (3.79liter gallon), and unleaded regular was US$2.32/gal

bhtooefr · « **Reply #6 on:** January 26, 2006, 03:23:46 pm »

I filled up Friday for $2.339/gallon.

Gas was $2.149/gallon then, IIRC, and now it's $2.019/gal. Haven't checked diesel, although I'm getting low.

Need to check air filter and wheel bearings, alignment and tires were done not long before I got the car.

bhtooefr · « **Reply #7 on:** January 26, 2006, 03:48:00 pm »

Injection timing was *JUST* set last Monday by MOGolf on the TDIClub forums.

As for the age of the injectors, I have no idea. However, the car only smokes when I want it to smoke. Wouldn't there be lots of smoke if they were the problem?

bhtooefr · « **Reply #8 on:** January 26, 2006, 06:24:03 pm »

Well, I'll take all of this into consideration, but before I finish deciding what my mileage is, I'll actually wait until my first tank is complete, and my odometer's fixed

dieselweasel · « **Reply #9 on:** January 27, 2006, 04:55:21 pm »

What is the approximate mileage of the engine?

bhtooefr · « **Reply #10 on:** January 27, 2006, 05:00:24 pm »

Estimated at 275,000 miles (440,000 km).

FWIW, I *DID* do a vented tank today. Assuming that my estimates have been right, that's 34.1 MPG. Pathetic.

bryanbryan89x · « **Reply #11 on:** January 27, 2006, 06:37:34 pm »

I'm getting 33mpg also with new injectiors, and with tires inflated to 40psi, combination of highway and city

bhtooefr · « **Reply #12 on:** January 27, 2006, 06:50:45 pm »

80% highway.

Tires inflated to max sidewall pressure of 36 front, 44 back.

And, almost BABYING it.

RabbitGTDguy · « **Reply #13 on:** January 27, 2006, 07:13:17 pm »

i'm dailying my 79 1.5 NA diesel... its not doing bad IMO for 48hp at 70mph ... averaging between 38-41mpg going west into the wind it seems all day long... Its so much easier when the wind is behind me

Thats with what I think to be tired injectors which will soon be swapped out...

Joe