How does the auto work?

pindie said:

What determines the change and lock up of gears in an auto box? Is it torque i.e. the more torque you have the earlier it will change up or is it road speed i.e. 30mph for third & 50 mph for 4th?

I am wondering whether or not to get a remap on my td5, if I do will it change up earlier and easier to try and save a tad on fuel. My td5 seems to always want to be around 3k rpm untill i back off. Its annoying.

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pindie said:

Thanks Dave,

My auto changes up at lower revs if you are super careful on the juice but it takes a calender to count the time to 50 mph. My td5 has a de cat pipe and no egr which has made it better which is why I wondered if was a torque issue.

It is no where as good as my old tdi 300 manual that had been modded as that flies and is great on juice at 30mpg. Td5 I am lucky to get 25 but its gone dark again by the time I get to work if I drive slow to get that figure.

I can see why LR went for a six speed box in the D3. I really can not see why people like the autos so much - loads of revs, loads of fuel and no gain other than being able to use your left hand to wave at people.

Thanks

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thebiglad said:

I'm not an expert on Td5's at all but on my Tdi300 auto (which I think is the same box) I run around at between 2 - 2500rpms comfortably. If you're having to run at those sort of revs something sounds wrong, unless you really want to get a move on, then maybe you are in the wrong car?!

If running at 3000rpm all the time this won't do any good for your mpg either?

A couple of things I've done on my car recently which has helped really noticeably, is to De-EGR and last week the biggest improvement was to De-Catt the exhaust.

I've just come back from a run out and I'm writing this whilst the auto-box drains and I find that, in relative terms, she's quite nippy now.


In terms of speeds for changes I find about 15mph into 2nd, 25mph into 3rd and 32ish into 4th. The torque lockup comes in at 52mph every time.

Hope that helps??!!

Cheers
Dave

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girvtheswerve said:

Hey Big

Ditto all those figures, they stay the same with big tyres aswell, bang on 52 for the lock up, but for me thats about 58 realtime speed, takes some getting there too.

How'd the froggy MOT go Big?

C

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