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Hi does anyone know the optimum speed or revs for a P38 4.6 HSE auto?
Ta
Ta
Optimum speed
- Thread starter oakey
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tomcat59alan
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For maximum efficiency or to blow it up?
Grrrrrr
Technician, Bodgit & Scarper Ltd
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Yeah, switched off on the drive. 
Grrrrrr
Technician, Bodgit & Scarper Ltd
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Speed-wise it is probably just after the torque-converter locks up. MPG figures are quoted at 56 mph so bet most car manufacturers aim to have maximum fuel-efficiency somewhere around there.
I'm guessing max-torque is probably around 3,500 rpm? So anything above that will be burning a lot of fuel for little benefit. I don't think most people take their 4.6 above 2,500 rpm though, you don't really need to and it just empties your bank account.
I'm guessing max-torque is probably around 3,500 rpm? So anything above that will be burning a lot of fuel for little benefit. I don't think most people take their 4.6 above 2,500 rpm though, you don't really need to and it just empties your bank account.
ukadamwest
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3250 RPM for max torque (Grrrr is close and wins a donut)
4750 RPM for max BHP
4750 RPM for max BHP
Grrrrrr
Technician, Bodgit & Scarper Ltd
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Looking forward to that.Of course, given you're trying to shove a barn-door through the air with resistance increasing as a square of the speed and the aerodynamics of a brick it is never going to win many prizes for efficiency!
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Of course, given you're trying to shove a barn-door through the air with resistance increasing as a square of the speed and the aerodynamics of a brick it is never going to win many prizes for efficiency!
Yep best MPG figures it will ever produce will be on the back of an AA truck when the liners slip.
ukadamwest
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Of course, given you're trying to shove a barn-door through the air with resistance increasing as a square of the speed and the aerodynamics of a brick it is never going to win many prizes for efficiency!
ohhh someone who know aerodynamics as well !!
tomcat59alan
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ohhh someone who know aerodynamics as well !!
Who told you that you could get off the naughty step?
ukadamwest
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Who told you that you could get off the naughty step?
no one.. i need to be chained down
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Who told you that you could get off the naughty step?
How did you get on Alan is it sorted?
tomcat59alan
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Not yet mate, she's had me decorating or should I say redecorating, did a room last week and she didn't like it the wallpaper when it was up so ...
. Haven't even had a chance to see the other P38 I was telling you about. Waiting for an injector spanner to arrive (someone has "borrowed" mine), got a bit of a leak from number one injector/head washer so will do everything at once. Will report back ASAP. Cheers. Mozz gave me a call the other day, said he spoke to you.
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Not yet mate, she's had me decorating or should I say redecorating, did a room last week and she didn't like it the wallpaper when it was up so ...
What sort of leak have you on number one?
300bhp/ton
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Nothing modern that is rated by NEDC standards does.
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Yes but the NEDC standard test is as accurate as the result of a three year old doing a quantum physics equation. It and the real world are light years apart.
300bhp/ton
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I guess travelling at a constant 56mph is far more realistic then...
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I guess travelling at a constant 56mph is far more realistic then...
You will be happy to know that the fuel consumption figures for my car almost exactly match Land rovers published figures. There have been several official test procedures in place over the years. Each would give a differing result. The latest EU directive circa 1997 is not seen as being the best. And gives results not obtainable in the real world. Or so it is said.
300bhp/ton
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I agree the NEDC leaves a lot to be desired. That said, in all the cars I've owned, I never had any trouble attaining or exceeding the published mpg figures. Although I'm also very accomplished at getting much lower too.
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I agree the NEDC leaves a lot to be desired. That said, in all the cars I've owned, I never had any trouble attaining or exceeding the published mpg figures. Although I'm also very accomplished at getting much lower too.
That is because the test is carried out on a rolling road, conditions are simulated rather than as the Land rover test was done on a test track in actual driving conditions. To be fair they possibly picked a good day for the test but at least the vehicle was actually being driven by a human and not by a bloody computer.
tomcat59alan
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Just a bit of bubbling between the injector and the head, showed up when the leakoff pipes leaked. Will remove the injector and anneal the washer, should sort it .
