i30 Owners Club
FUEL ISSUES & ECONOMY => DIESEL => Topic started by: terry hunter on June 24, 2009, 01:29:32
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First chance to check economy since new in April, sees the wagon getting 5.15lt per 100km... which I suppose is OK.
Car has done just over 5000km, no passengers, tank dribble filled to top both times, cool overcast day, no wind, few hills, mostly freeway with cruise control set to 100km.
As the wagon is a bit heavier and bigger than the hatch, it is listed to be a little worse on fuel than the hatch (av. 4.9 vs 4.7) so am keen to see the improvements as the motor wears in more.
Does anyone know the optimal cruising speed to achieve maximum economy? I know that in 5th Gear, at 100kph the revs sat at 2250, and I'd have to drop back to about 90kph to get it to on or below 2000 revs.
Terry H.
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Hi Terry
I think you're doing the right thing already. Max. torque is when the engine is using its fuel most efficiently and that's between 1900 and 2750RPM on the 1.6 CRDi. So, 1900RPM equates to the the lowest speed and therefore air resistance when the engine is at it's most efficient. Maybe keeping it at 2100RPM (~95kph?) will be a practical compromise to allow for slight uphill gradients without having to change down a gear or dropping into a less efficient RPM range.
Mick
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Hi Guys I was going to say 90 to 95kph as the optimum recommended economy cruise..from the reading of some of the thousands of posts on here...
I'd be happy with the 5.15 LPHK
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Hi Terry
I think you're doing the right thing already. Max. torque is when the engine is using its fuel most efficiently and that's between 1900 and 2750RPM on the 1.6 CRDi. So, 1900RPM equates to the the lowest speed and therefore air resistance when the engine is at it's most efficient. Maybe keeping it at 2100RPM (~95kph?) will be a practical compromise to allow for slight uphill gradients without having to change down a gear or dropping into a less efficient RPM range.
Mick
Terry and others...
Logically it makes sense that the best fuel economy will be had at or around the revs you mention. However, I have found it is not the case. I can achieve best economy by watching the MAP (manifold air pressure - as reported by Scanguage II) and keeping it as close as possible to air pressure (zero boost). Cruising at around 80-90kph on the speedo (more like 75-85kph on a GPS) and using the accelerator to control MAP, backing off a little up hills and accelerating lightly down hill is the optimum. Of course, using the Scanguage, I can watch real time fuel consumption as well.
Now, I am talking unrealistically low speeds for most drivers. I am sort of on an economy kick and have been for just over 12 months now. This morning I got 4.1 LPH on the way to work and 4.5 on the way home, with an overall average of 4.3. Yesterdays average was 4.4 LPH. Average speed for the 150km round trip are usually about 68-72kph. It takes me 5-10 more to get to work but I feel much safer as I see roos and stray stock (country roads) in plenty of time to avoid them.
I know I am a bit obsessive. I wonder what I could eek out of a cw?
Bob
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Now, I am talking unrealistically low speeds for most drivers. I am sort of on an economy kick and have been for just over 12 months now. This morning I got 4.1 LPH on the way to work and 4.5 on the way home, with an overall average of 4.3. Yesterdays average was 4.4 LPH. Average speed for the 150km round trip are usually about 68-72kph. It takes me 5-10 more to get to work but I feel much safer as I see roos and stray stock (country roads) in plenty of time to avoid them.
I know I am a bit obsessive. I wonder what I could eek out of a cw?
Bob
Hi Bob.. I'm guessing we are talking very level roads with few hills?
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Thankyou all for the informative and helpful posts.
Probably like most of you, I swing between the challenge of lowest fuel consumption (with accompanying bragging rights esp. to non-crdi motogs), the practicality of not spending all my life in the slow lane, and the pleasure of the surge of the turbo and some nippy driving!
As driving is a "right brain" activity (requiring constant creative choices) rather than a "left brain" (ruled by patterns and logic), the i30 crdi certainly keeps me amused... along with numerous others belonging to this forum... :razz:
... off to Melbourne to cart another tonne of stuff back tomorrow.... and while the i30 doesn't need changing down on hills even with a load, it certainly sips a lot of extra fuel.
But hey, what am I complaining about when I see all the guzzlers around me with no load and still poor economy!
Only wish I could quickly and easily alter the headlight beams for when the back is loaded.
The scewdriver fix before and after is not exactly a real solution.
Does anyone know if it's possible to import the auto headlight adjusting kit from Korea as an aftermarket fit?
I can't find anything on the net about one.
Maybe I can make and fit an "eyebrow" cover for the headlights for this purpose...
Terry H
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Hi Bob.. I'm guessing we are talking very level roads with few hills?
Dazz,
Your right, but I guess you knew that anyway.
Bob
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Does anyone know if it's possible to import the auto headlight adjusting kit from Korea as an aftermarket fit?
I can't find anything on the net about one.
Maybe I can make and fit an "eyebrow" cover for the headlights for this purpose...
Terry H
Hi Terry,
Seems to be a European thing.. for some reason they don't think we need them here :rolleyes:
Don't know of any member who has retro fitted them so far....