I started driving on Minis and the inner joints on those were rubber cruciform types. They were clamped in using U-bolts and if not properly aligned would cause the shaft to run out of true. This had two effects : firstly they would be out of balance, although as they were relatively light weight this didn't cause much of a problem. The other effect was that it cased the wheel rotation to be very slightly uneven which reflected through the steering as a wobble. This was noticeable at low speed more than high. The joints were always troublesome because they got oily, the rubber swelled and they started knocking on the transmission casing.
Modern shafts use the tripod joints with needle roller bearings and don't, as far as I know, suffer from misalignment but as you seem to have eliminated wheels and tyres as the source of the problem I just thought it would be worth checking to see if the shafts are running true or, worst case, bent. The only way I know of is to jack up and turn the wheels whilst looking at the shafts.
Assuming you've checked for distorted wheels I'd have thought the next place to look would be the driveshafts and their joints. As the vibration is noticeable from such a low speed I'd check for the shafts running out of true and have a close look at the inner tripod joints.
For some time now our 03-plate Mk1.5 Ghia estate 1.8TDCi has suffered from a bit of steering vibration. It recently had an MOT and came away with a clean bill of health but needed new front tyres. The front wheels have been re-balanced three times since then but the vibration is still there. It happens from about 65 indicated upwards and is not constant, sometimes it's worse, sometimes barely noticeable. I have noticed that on a gradual bend in the road it comes and goes as though the wheels are going in and out of sync.
At the last balance I specifically asked the the guy to check that the alloys were undamaged and running true and he confirmed they were ok. Also as far as I know the driveshafts are undamaged.
I'm now wondering if the problem is the suspension getting a bit tired and slack - the car's done just over 105K - and therefore less tolerant of any slight imbalance in the wheels and shafts. I just bought a 60-plate Mk2.5 hatch and the handling of that feels so much tighter and more responsive and although I realise the steering geometry is probably different the older car feels distinctly soggy by comparison.
In spite of the clean MOT I wonder if I should have the front shocks replaced. If so what brand should I go for? I notice Euro Car parts list three different makes.
Also on a side note: i spoke to an environmental chemist in work and asked him whats his view on DPF,
He reckons the self regeneration process is actually worse than having no dpf because it drops a bomb of toxic gasses potentially in a built up area instead of cosistant low levels,
He also says turning carbon in to gasses it worse for the ozone,
This is precisely why I decided not to buy another diesel. Don't get me wrong, I love the driving characteristics, torque and economy of our 1.8TDCi but I think diesel emissions are far more injurious to human health than a petrol engine and the measures taken to try to overcome them are both ineffective and expensive. For a long time now I've had the suspicion that the increase in breathing problems such as asthma is at least partly linked to the use of diesel engines, in the haulage industry and public transport as well as increasingly in private cars.
The blue filter layer on these lamps is intended to make the output look whiter by absorbing wavelengths in the yellow region which is where the light output peaks so they must actually give less light than bog standard ones of the same wattage. The energy absorbed will also make the envelope hotter. The only way to get a whiter light without these absorption losses is to run the filament at a much higher temperature which will inevitably shorten its life.
Personally I would avoid using engine flush. When an engine is drained not all the oil is recovered. Some remains in oil galleries etc.This is why in the service manual there are different quantities quoted for filling a dry engine compared with refilling after an oil change. This is part of the reason new oil turns black so quickly and means that some of the flush will be left behind and dwindling traces will remain for several oil changes thereafter.
I think martyntdci has put his finger on it. Diesels are most fuel efficient on really long trips. We took our 1.8Tdci up to Scotland earlier this year and the mpg went up to 65. At home it varies between 47-52 and never goes above 52 even on a 50-mile trip on mainly low-speed local roads. Just a trip down to the local supermarket instantly knocks it back.
whenever a bulb has blown the resistance on the circuit decreases and the voltage increases causing the bulbs to flash faster and brighter.
If you were to add more bulbs to the same circuit the resistance would increase and voltage decrease causing all bulbs to flash slower with less lumens.
Actually it's t'other way round - since the bulbs are wired in parallel when one blows the resistance in the circuit increases and the current decreases. Adding more in parallel would decrease the resistance and increase the current.
In the days when I first started driving the flasher units were simple bi-metallic units so the flashing speed was directly related to the current passing through the unit. A higher current would make the bi-metallic strip deflect further and take longer to return thus slowing the rate. A lower current would deflect it less and it would return more quickly. That's where the idea of rapid flashing when a bulb blew originally came from. Modern units are electronic so I'm guessing this has been deliberately designed-in.
From what I've read elsewhere it seems fairly likely that supermarket diesel lacks the additives that are put into branded fuel. I don't use it unless it's an emergency "splash and dash". It's interesting that the garage that does my service offered me the Forte treatment but when I said I only used branded fuel they replied that I didn't need the treatment.
Don't be fooled by the 'it all comes from the same tank' either. The additives are apparently added to the tanker which has separate compartments for the different retailers.
Arthur's absolutely right. We have a run to our daughter's house of almost identical mileage and mix of roads. The best we achieve is 52-55mpg so your result looks about right. If I pop out to fill up the mpg shows a hit a few miles after we set out for home then normally recovers by the end of the journey. Journeys to the local shops & supermarket soon knock it back to 45 mpg or less. You'll also notice that the calculation lags by a few miles. You may find it goes up a bit on a short journey that follows a long one before it starts to drop back and initially drops at the beginning of the next long one..
Unless your air filter is seriously clogged I can't see it having a noticeable effect on your consumption.
I know its not scientific or the best way to do it, but last week I put £35 worth in, when the trip said it had about 75 miles left to empty. A week later, when it said 75 miles left, I'd done about 242 miles. The £35 petrol (@ £1.359/litre) was 5.66 gallons.... 242 miles divided by 5.66g = 42.7mpg. The trip is saying an average of 41.5mpg, so it cant be that far adrift, can it?
Bear in mind that the range figure is calculated from the average mpg figure so it's no surprise that they are in step. The only accurate way is tank brim to tank brim. The trip is useful for seeing how it goes up and down in different scenarios and driving styles.