Bracechenko
Member Since: 29 Jun 2021
Location: Cardiff
Posts: 178
  
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| Worse Fuel Economy after timing belt replaced |
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As the title says really. Had the timing belts changed and the fuel economy is noticeably worse. Car drives great, pulls really well, no smoke or driveability issues but I'd say the MPG are about 5mpg worse than it was before.
Do new belts need 'bedding in' or could this be something else?
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 14th Oct 2021 1:57 pm |
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lynalldiscovery
Member Since: 22 Dec 2009
Location: Maidstone
Posts: 7274
 
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Are yopu sure everything is plugged in/hoses connected etc?
It is also that time of year when mpg drops as the temperature drops, and if its cold enough (sub 7degc) the FBH fires up.
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| 14th Oct 2021 2:29 pm |
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Bracechenko
Member Since: 29 Jun 2021
Location: Cardiff
Posts: 178
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Pretty sure all hoses are connected. The temp is lower and the last long run I did was a few months back....could that really contribute to 5mpg?
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| 14th Oct 2021 3:27 pm |
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eightfoot
Member Since: 12 Apr 2015
Location: sunny essex
Posts: 770
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also dont forget the cost has gone up somewhat recently
i recently paid £1.55.9 ltr for esso premium diesel and i dont expect the price to fall anytime soon (ever)
i think the days of big engined diesels are coming to an end,have you seen the cost of crude oil today dont think ive seen it this high ever   please excuse any grammer/punctuation mistakes,i'm thick,thankyou
current vehicles 2005 d3 2013 d4
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| 14th Oct 2021 3:59 pm |
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aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2459
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How are you measuring mpg ?
If your just going by whats on the dash, it works out the average mpg since the system was reset. If the system hasnt been reset for a long time it doesnt change very much even if you drive really uneconomically.
When you had the belts done they disconnected the battery and reset the system now small differences in driving style averaged over the miles driven since reset make a big difference. Andrew
D3 2.7tdv6 2005
D4 3.0 SDV6 Commercial died and gone to LR heaven
D5 3.0 SDV6 HSE
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| 14th Oct 2021 6:13 pm |
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Bracechenko
Member Since: 29 Jun 2021
Location: Cardiff
Posts: 178
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Hi guys, thanks for the responses. It's nothing to do with fuel price as I'm not really tracking miles against £££'s spent as that changes as you say. I am using the onboard MPG average in the car. Now, I know that it's not accurate so whatever MPG is states comes with a pinch of salt but I would be under the impression that you could at least use it relative to itself if that makes sense?
Ie, in my case a motorway run used to give me 35-36mpg with the onboard and now states 30mpg for the same run. I know that those figures may not be correct (due to the inaccuracy) but surely the movement between the 2 numbers on the same device is useful?
I have had an awful lot of work done to the car in quick succession as I've bought it and thrown my wallet at it hoping to have it give me a number of years of happy motoring so it's going to be difficult to pinpoint this fuel consumption change I guess.
As mentioned though, it differed after the timing belts were changed but I have also had a horrible fuelling/throttle response issue which felt like a MAF problem but seemed to cured itself just before I took it into the garage for the timing belt.
The car now drives absolutely fantastic and exactly how I expected it should drive. I wonder if it was perhaps running a bit lean due to a MAF issue...could this have given better MPG and now what I'm experiencing is "normal"?
I've only had the car a few months so can't rely on previous experience of how it should be. However, right now it pulls like a train (helped along with BAS remap - and no, that was done before I noticed this MPG change), the gearbox is sweet as a nut and the throttle response is finally back to what I'd expect. No smoke, no noises, very strong and a perfect ride. I should probably stop faffing and just be happy it's where I want it to be 
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| 18th Oct 2021 9:16 am |
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