I have just read a discussion on whether diesel or petrol cars are easier to drive. My Mondeo TDCi Ghia Estate is powerful and excellent on the open road. Give it some revs and it can take off from a standing start like a rocket. BUT it is also quite easy to stall in traffic, e.g. when pulling away gently in 1st, and it does not have the flexibility to pull smoothly in 2nd when the wheels are just turning. In 3rd it is not happy below 20mph. It just seems to lack the flexibility which diesels are famous for. I'm guessing that this is just the downside of a diesel designed more for performance than smoothness. I also have a Focus 1.6 (petrol), which is much smoother, more flexible and easier to drive in city traffic. There are lots of Mondeo TDCi's out there, and I'd be interested to hear if any other drivers have similar experience, especially on the off-chance that my car has a problem that can be fixed!
|
I have a focus TDCi and this is also how you describe your mondeo. Previously I had an indirect injection Polo diesel and that hardly ever stalled. You could go at just over walking pace in 3rd.
Try that in the focus and you stall. Another anoying thing is the way my car accelerates by it'self when you engage say 2nd at low speed. It surges forward and then slows down a bit to the speed you expected it should go at, all without you touching the accelerator. In slow traffic you know how fast it is going to go on a neutral throttle but end up leaving a large gap so it can speed up and then slow back down again.
James S
|
|
|
I test drove a TDCI 130 Mondeo, and stalled it several times with the dealer sitting there. He said all diesels need throttle to accelerate even on the flat.
Thats funny because the 5 turbo diesel Citroens I have driven would go into 1st without throttle, you could then change into 2nd and 3rd only using your left leg. 4th gear without using the throttle is too jerky however.
The TDCI has been recently redeveloped to reduce this and the starting problem according to AutoExpress.
Ben
On my 3rd Citroen. Saxo, Xsara, C5.
|
"the dealer sitting there. He said all diesels need throttle to accelerate even on the flat."
Don't ALL cars need throttle to accelerate on the flat?
On the other hand, you should be able to engage 1st
(with warm engine) release clutch, and proceed at about 4mph.
I simply do not understand the idea of attempting to engage 2nd and 3rd gears
at too low a road speed.
To achieve what?
|
|
|
|
"it does not have the flexibility to pull smoothly in 2nd when the wheels are just turning. In 3rd it is not happy below 20mph."
That sounds exactly right to me. 30 in 3rd sounds about right.
|
Yes, every diesel I know can pull in 1st gear without throttle action and just the clutch. This is also possible in a decent petrol car, but is not as easy to do without stalling.
Can anyone suggest why this is the case (technically).
|
Yes, every diesel I know can pull in 1st gear without throttle action and just the clutch. This is also possible in a decent petrol car, but is not as easy to do without stalling. Can anyone suggest why this is the case (technically).
A lot of it is down to the size of the flywheel. The smaller the flywheel, the more easy it is to stall. Take Formula 1 cars for example. They have poxy flywheels and can stall simply by just letting the revs drop too low.
|
Further to reasons for not stalling:
the engine management will try to maintain correct tick-over speed - say 800 rpm, as part of emission control.
"Normal" loads which would alter the engine speed:
aircon, lights, hrw, fan..
|
I stalled mine two or three times on the first day of ownership but thereafter got used to it. The TDCI doesn't have a throttle cable as I've since been told and its all done electrically ("fly-by-wire"?) and it takes a bit of getting used to. If you apply the throttle, the uptake on revs is slower than on my last diesel but only takes a bit of getting used to, so put your foot gently down, listen for an uptake in revs and release the clutch. (sounds like my first driving lesson). This does not mean its inflexible & doesn't hinder rapid acceleration/handling. However, if you want a rally car response, a diesel is obviously not for you!
Never stalled since first day, and I have to say the TDCI just gets better & better every day. I am surprised that the performance gap between this car and a family member's BMW 530d (which I went in today & which is a fine car indeed) is much smaller than I imagined.
Splodgeface
|
|
|
|
