01-10-2013, 10:30 AM | #1 |
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why i like my 116d (non ED) - the economy
thought I'd reset my trip computer when i set off from work today - 69.9mpg averaging 53.4mph over 13 miles - from cold - in rush hour!
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01-10-2013, 10:55 AM | #3 |
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01-10-2013, 11:17 AM | #5 |
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Drives: F20 120d
Join Date: Nov 2012
Location: Norway
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I don't get anywhere near numbers like that. My commute is about the same distance, and under normal circumstances I get around 49 mpg (5,8 l/100km). If the traffic is very light, I can push it to around 59 mpg (4,8 l/100km).
My 116d is an E87 but it's the same engine, so there shouldn't be much of a differences in consumption under equal conditions. My daily drive is quite....hilly, and that doesn't help. |
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01-10-2013, 02:05 PM | #6 |
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That's pretty impressive orcomma, I shall strive to improve on my best which was 71.3 mpg averaging 52mph in 29 minutes covering 24 miles in comfort mode.
That was in my ED which they say can achieve over 80mpg! That remains to be seen though! |
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01-10-2013, 04:23 PM | #7 |
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All fuel economy will improve in the summer - mine was about 10% better last summer. How many miles has your ED done?
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01-10-2013, 04:58 PM | #8 |
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It depends on the cold starts. Most of my personal consumption records are set on cold winter days, with winter tyres, on long trips with no cold starts.
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01-11-2013, 03:20 AM | #10 | |
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My son runs an Audi A3 Sportback S-line with the 140TDI engine, similar sort of combined figure as the 116d. He can get near to 70mpg on a very steady drive as driver only, but the real average is mid 50's for day to day driving, and that is in light driving conditions. Getting genuine mpg returns around the official combined figure requires a light throttle, keeping the speed down (not typical BMW speeds) and light conditions. Mpg shortfall is normal for most drivers. HighlandPete Last edited by HighlandPete; 01-11-2013 at 03:46 AM.. |
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01-11-2013, 03:49 AM | #11 | |
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Think my problem is many years ago I had a MK4 TDi Golf and got high 60's in that, even had 50 (iirc) going from East of Germany to West of Germany at 200+ kmh... |
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01-11-2013, 04:08 AM | #12 |
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I think the combined factory figure does not involve cold starts. In the real world you typically start the car cold every day, which make a huge impact on the consumption, particularly on short trips.
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01-11-2013, 04:18 AM | #13 | |
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You mention the MK4 Golf TDI, my son ran an 110TDI GT for 4-years, a model that was so easy to exceed the combined figure. He'd see figures into the 70's driving to work without effort, and that was back between 1998 and 2002, before we entered the age of "the efficiency drive" and pre ULSD fuel. I recall his highest figure was over 90mpg on a run to work at the best ambient temperature (16C) one summer morning. The VW 1.9 TDI was a very fuel efficient engine ahead of all the emission improvements, had one of the best BSFC figures, achieving 195g/KWH at best point. I had a VW B5 Passat with the 110TDI engine, my consumption was typically around 60mpg on many trips. My best was from the Highlands to Warwick Services (about 400 miles) where I recorded 68.9mpg one summer day driving at legal speeds. Yes, 68+mpg without effort, back in 1999 from a car much bigger than the current F20. HighlandPete |
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01-11-2013, 04:42 AM | #15 | |
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Cold starts and high electrical loads in winter can typically knock off the 10% that has alreay been mentioned in other posts. I've seen that sort of difference on seasonal changes, in several diesel engines, and that can be 5mpg or more in reality. Just to show how a cold start and ambient temperatures affected my 330d. From home to the next village, a trip I'd repeated hundreds of times. Reset OBC and reading at village, 3-miles from home. Cold start around 0°C OBC reading 25-26 mpg. Cold start approx’ 10°C OBC reading 29-30 mpg. Warm start approx’ 10°C OBC reading 34-35 mpg. Hot start at approx, 10°C OBC reading 37-38 mpg. Note that is a spread of about 13mpg over the first 3 miles from a start, just covering a 10-degree ambient range. Obviously the mpg reduces the spread over higher mileage from start up, but still over a 5mpg spread at around 12 - 15 mile trips, using the above examples. HighlandPete |
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01-11-2013, 05:03 AM | #17 |
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01-11-2013, 06:08 AM | #18 |
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01-11-2013, 06:25 AM | #19 | |
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Have you actually run any brim to brim calculations to establish your true average? You can then adjust your figures if you know the +/- error of the OBC. Then when you drive the motorway you can reset, and see how much mpg you actually are achieving at ~70mph, adjusting for any OBC error. An E90 318d saloon driving at a contant 70mph is reported to give 53.9mpg in test conditions, so an F20 116d won't be too much above that in controlled conditiions. The 1-series doesn't do too well at speed from many reports. Some who have run both 1 and 3-series find there is virtiually no gain at motorway speeds in the smaller 1-series diesels. Aerodynamics don't help and the engine will be running a bit more boost than the 120d at that loading, so another negative. Lowering the speed is where the smaller engine will start to march ahead on mpg. HighlandPete |
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01-11-2013, 07:56 AM | #20 |
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My commute is 70% motorway, 30% urban. the motorway was pretty clear (i go in the opposite direction to rush hour), 65-70mph on cruise weaving in and out of the occasional car. For the 30% that was urban, it was a nightmare, buses and traffic lights. When leaving the motorway i had it at 72.9. It dropped to 69.9 in a mile of urban traffic. If I were going further than that, it would probably drop further.
But at least it shows decent economy is achievable with careful cruising. And it kicks the ass off my mate's Audi A1 1.6TDI which he struggles to get above 52mpg even when driving like a granny |
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01-11-2013, 07:58 AM | #21 |
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cold starts arent the only thing that affects economy in the winter - the denser air requires the ECU to inject more fuel to keep the same fuel/air ratio. The result is worse economy but (theoretically) slightly more power!
also the engine loses more parasitic energy in the form of heat loss - it becomes less thermally efficient. however the increased AC drain in the summer often offsets at least part of the warmer seasonal benefits. but for this journey it was a cold start, car had been still in the office carpark since 8am lol |
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01-11-2013, 08:14 AM | #22 |
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