120 MPGus in my car seriously possible?
 

Been looking around on the 'net for more info on the Astra ECO4, and found some news that someone achieved 120 MPGus / 144 MPGuk / 1.95 l/100km in an ECO4 in 2001. Keep in mind the combined EPA (old style) ratings for this car is about 53.5 MPGus, and this car is a plain vanilla turbo diesel hatchback with some aero mods stuck on after the car was built and designed literally as an afterthought, so is this figure at all realistic and possible? Or is it just fluff from GM? It just seems outlandishly high to me and sounds extremely unlikely as it easily outstrips most cars designed with fuel economy in the mind from the start.

Info from GM here at the bottom of the page, and a reference here (note figures in 2nd page is in MPGuk).

Sure, if you average something like 10 mph on an oval track lots is possible :thumbup:

I think a great hypermiler can do that.

These folks were out on the road in presumably stock cars.

No mention of average speed but I'm sure they got into top gear which would be quite a bit more than 10 mph.

being ex-vauxhall and a big fan of the 1.7dti lump I think it would be possible, I love the way the estate version I had can out-eco a hybrid, produce sub 130g/km and all this from a salesmobiles with an engine thats been around since the very earlier eighties if not before( and is still going).

BUT that said I don't think it'll be a completely stock one. I think EXTENSIVE hypermiling techniques, trick tyres, long box, alternator slipper, different undertray (i know the Eco4's had a basic one over the Std cars) and maybe a trick ECU map matched with a shadow car providing a perfect draft...... but not carrying any any Opel decals/IDs ;) (guessing)

Darin has gotten those numbers in his geo "out on the road" at an average speed of like 20 mph, however, he also called it incredibly impractical driving, etc etc.

Now, I would love to see what figures Wayne Gerdes would get out of an ECO4.... both modified and unmodified. Now that'll be interesting.

Cheers to all for comments.

As you've driven the 1.7DTi lump before, how long should it take to warm up? It takes my engine 10 mins of driving before the thermometer needle start moving from its rest point of 70 degrees C and a couple minutes until it reaches 87 degrees C, even though I always turn the blower to off and the heater to full cold until the engine's warm which causes me to suspect the thermostat. However, on a cold day once the engine hits 87 degrees C, I turn on the blower to maximum heat, the engine temperature drops fairly quickly down off the scale making me think it's not the thermostat after all, just the engine not producing much heat. Your thoughts? I know I can test the thermostat, but wanted to see your opinion before having to drain the cooling system and risk burning myself by sending the thermostat for a swim.

My recolection is that it took my dti roughly 8mins (5 on Mway) before the car had reached cruise temp - I too noted the effect of switching the heater on had on engine temp- its like a second radiator I used it in heavy M6 traffic to kepp temps down. simply put heater and blower on full and open only the passenger face vent and blow it out the passenger window!

if you want to bring the temps up quicker try altering the water/anti-freeze mix

So you would say the thermostat is working fine? As it took my Civic 2 minutes to reach operating temp, but then again that was an aluminium petrol engine that drank petrol, while the DTi engine is cast iron - more dense metal to warm up. I had an eye on the clock today - took 17 mins for the engine to reach normal temp - 15 mins city driving, and then 2 mins dual carriageway, ambient temperature was about 16 degrees C. I probably will test the thermostat to make double sure it's OK anyway.

I remember several years back in my Nova, the fan thermostat switch failed on the hottest day of the year (30 degrees C IIRC), and I was stuck in a 2 hour tailback for a mile. The engine kept overheating and I had to turn the blower fan on full. I nearly got dehydrated - I didn't have any water with me! I was wishing I had a paperclip with me on that day, I would have been able to short out the thermostat plug.

Thanks for advice!