IDI engines: fuel economy comparison

[wikdslo]

My 81 diesel just got me 4.223L/100km for primarily highway travel at an average of 95km/h.
And 5.2L/100km on a mixed 85km/h average through a hilly mountain (200km), and 105km/h for highway travel (400km).

[Turbinepowered]

Or 5.72l/100km is 102.803577 rods per fluid ounce. I love the calculator too.

I want a speedometer that measures Rods per Hour.

[carrizog60]

1988 golf gtd
JK engine converted to TD
modified,136hp on fly

best 4.8/100km

[GTD0023]

Hey guys,
need some advice....
what can i do to get my fuel consumption down?
will a better air filter make a big difference?
what's the best choice? and what about my exhaust, should i go biiger than stock?, i know it will help my performance but will it do any good to my mpg.
My car does 6.6L/100km. I would like do do 5 or something :wink:

and what about pump timing??

[Turbinepowered]

It's a DI, even common rail, but just for comparison...

My diesel ride nets me 44L/100km. No, that isn't a typo, I did indeed mean to type forty four.  :lol:

[Zulfiqar]

1985 golf 1.6 NA (hyd) 4.6L/100 kms city - with light foot

injectors some ND 135 bar breaking pressure
pump redone by same oldschool veteran who did the injectors

5L/100 kms on highway doing 130 or 140 depending on the wind.

mk1 golf 1.6 TD (with nasty 11mm pump) and bosio SD274 nozzles and some petrol engine gearbox with tall ratios

6.5 or something litres/100 kms city

7 or 8 L/100 kms highway with punched throttle going till 6000 revs

[gldgti]

my new mk3 TD aaz just got 6.38l/100km on its first tank with me, gunning it around trying to see how fast it goes. it runs 205/45 r16's

my old '79 gld n/a 1.5:

best - 4.5l/100km
worst - 6.6l/100km
average - 5.4l/100km

with big exhaust, cold air intake, 185/60r14 sticky rubber and aggressive alignment.

cheers

aydan

[Black Smokin' Diesel]

Ok 87 Jetta 1.6TD with mercedes 130 bar injectors, pump timing at 1.00, K24 with stuck wastegate (yeah it died last week  :? ), fuel screw turned in a lot and LDA pin on the aggressive side, Falken Azenis RT615 195/60/14 tires (very sticky, not a hard compound) on Ronal R8 rims (pretty light I must say) and idle speed of 1100.

City: 8-10l/100km, it varies quite a lot depending on weather and my mood
Hyghway: 5,5-6l/100km @ 110kph

Yeah I drive it like I stole it in the city, that explains a lot :lol:

[92Wolfsburg]

96 AAZ Jetta - 42mpg US highway
92 wolfsburg jetta - 50mpg US highway

[tylernt]

I do 99.9% city driving in an '82 Rabbit, FF code 5spd, recently rebuilt injectors. In the winter I get 39 (US) MPG and in the summer, 43 MPG. I didn't seem to lose any economy with pre-ULSD 100% petrodiesel a year ago vs B20 ULSD today.

I do have a rear tire with a slow leak, so it's chronically low. One of these days I'll fix that and I bet that will net me a few MPG.

[alphawerks]

Been a while since posting, but here goes.

90 jetta MF, pump mods (several), straight pipe, leaky tires(3).

Best:    4.1l/100km  1256km/tank(52l)
avg:     4.9l/100km  1000+km/tank(50 - 53l)
worst:  6.2l/100km  850ish /tank   :?  
All measured over a whole tank.

Generaly hohum driving, pulling trailers, pulling logs for firewood, collecting bales in hayfields ect., with the occasional jaunt to 6000 rpm at 24psi. (still pulls hard at 170, not tried more)

Ryan

[windex]

96 Golf III AAZ TD

Somewhere around 400k (cluster says 25k, but registration records show previous' at 400k 6 months ago)

four tanks worth so far averaging 39mpg (US) mostly city

with wobbly 195 60r14 tires and a bad wheel bearing

It's now shod with 185 70r14 (yes they fit) at 40 psi, new .270 nozzles, and the pesky wheel bearing has been replaced.

Hoping that I can maintain ~40mpg city going into the winter with the taller tires and a light foot - will update progress...

Kinda depressing to find that the AAZ MKIII's were about the worst (mileage-wise) Diesels that VW made, going by numbers from this thread mkI NA - 50mpg, mkII 1.6 TD ~45 MKIII 1.9AAZ ~42mpghwy... ALH TDI's back up to 45-50mpg.  I had a 2006 jetta PD 1.9, and regularly got 52mpg (4.8l/100) highway, and it was a much heavier car...  

Hopefully things will improve somewhat...  However, it's still loads better than my previous saab, getting 10l/100 city.

[Jet-A]

I have an 82 MK 1 Jetta. 4 door, ac, sunroof. Weighs about 2200 lbs. 5 speed and 330K miles on car/engine. Lifetime average approx. 42 MPG. I do flog the daylights out of it as I drive 110 miles from my home to Seattle at speeds of 70+ mph. Was on a site the other day talking about "hypermiling" and it had some tips. The usual suspects, tire inflation, remove excess weight, tune ups and synthetics plus it advocated several controversial methodologys that included coasting with engine off, minimal braking (consistent with safety) shutting down the engine and drafting. So being the idiot that I can be I tried them. Before anyone goes off half cocked the drafting was PRUDENT--maintained approx. 6 car lengths for 60 mph and was very attentive. Result for my typical commute went from 42-44mpg to 59! I thought I screwed up the math and did multiple rechecks and ran another test, this time 57 mpg. This is definitely slower than I normally drive but it validates the efficiency of these great engines.

[tylernt]

Another possibility is adding a belly pan to the underside of your engine bay to reduce drag. However that can be dangerous too as it can allow your car to "lift" like an airplane wing and lose traction at high speeds. But, apparently there are some worthwhile gains to be had there too.

Your Mk1 definitely has a weight advantage. As you noted it's barely over 2,000lb. The Mk2 gets closer to 2,500lb and the Mk3 and Mk4 are around 3,000lb. However the newer cars also usually have alloy wheels instead of steel, and larger rim sizes as well which improve economy (less weight = less rotational intertia). So obviously the best combination is R15 alloy wheels on an older car.

[Fionn]

Hi,
    I've often thought a belly pan would be a good idea, would help to keep the engine bay nice and clean too!
Any pics of installed pans?