Bought a new car yesterday to replace the Accord - picked up a VW Passat 1.9 TDi 130 with 90k on the clock. Delighted so far but wondering about the best way to drive it for optimal fuel efficiency.
Fairly spirited driving around country lanes and A-roads has led to an average of about 45mpg, but driving the same roads very carefully and essentially "mimsing" along only gave 38mph.
Is this due to the characteristics of modern diesel engines? I used to have a 1.9TD Xsara, but that did 45mpg no matter how I drove it.
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You are back in the UK then David ?
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Yep - arrived back in sunny England on Saturday. Haven't caused any major incidents yet (apart from nearly turning left on a red light - oops).
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So did you sell the Honda before you left or have you just recently traded/sold it ?
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90k miles? I think it needs time to be run in.
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I've got an older Golf TDi 90 that seems to do 50 whatever you do to it. Rather useful really. The newer 2litre 140 bhp diesel is a wholly different thing. Much more variable. I think you may find that too low revs (labouring the engine a little) uses more fuel than being in the 'sweet spot' around 1700-2000 rpm. Absolute max economy in the 2 litre is actually around 35-40 mph in fourth gear. Too slow for everyday but sometimes I come home after night work at this speed through country lanes. Had it up to 70 mpg over 50 miles including steady 50 mph on dual carriageway. I expect others will echo my findings but acceleration kills the economy. Nice and gently, letting the engine pick the speed up, if that makes sense.
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Actually, the Honda is still safely tucked away in the barn! I've got 2 weeks off so I'll get it valeted and stick it on Autotrader. It's actually my brother's Passat (he's gone and bought an A5, the sod), and I made him a silly offer which he accepted. So much more pleasant to drive than the Honda - my driving style suits diesels, I think, and it glows blue at night. I'm easily impressed.
I rode in a Passat of similar vintage in Tunisia a couple of years ago. After talking to the taxi driver, it had been around the clock (in km) on the original engine.
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Is it a 5- or 6-speed gearbox?
The PD130 engine in my old Passat B5.5 (2003 model) gave the best economy by accelerating briskly to the desired cruising speed, then you can ease off the pedal so it cruises on a whiff of throttle.
If you mimsy around, accelerating gently etc, you can see the impact on mpg on the instantaneous fuel consumption display.
Mine used to work best in the 1750 to 3000rpm range, it very rarely needed revving higher. I found the engine had a sweet spot at 2700rpm, which was an 85mph cruise in 6th gear. It would give 50 - 55mpg at this pace. It gave me 46.5mpg average over 60,000 miles driving.
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My 5 speed B5.5 100ps gave 44mpg overall and never varied much in the 110,000 miles I did from new. Envied those who claimed to get 55mpg!
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