Simon1975 said:
Just thought I would share this info.

I fitted a PSI Powerbox a few hunderd miles ago and the dash said 27.7 at the time and was on that figure for a month or so.

It has now risen to 28 and it may keep going up with a bit of luck.

So I'm very happy to have extra power and better fuel economy.

:)
Click to expand...

Whoopee Dooo's, a whole 0.3 mpg increase (if your really lucky you may see 0.5 mpg), increased power requires increased fuel usage....as Warmers said.....SIMPLES...:eek:

Simon1975 said:
I'm afraid I do not agree with that. The way I drive the car is not full on by any means, and with that style of driving the fuel economy is better with the PSI installed.

e.g. Rather than having my foot to the floor in the past to struggle up an incline at 55mph, it now cruises up nicely without excess throttle.

I do however understand what you are saying.

But the PSI Powerbox is supposed to use the fuel more efficiently than the original set up, hence better preformance and fuel economy.
Click to expand...

I live in the flat lands of Essex but do escape to more hiller country, went on holiday to the south coast (3 adults, 2 kids and luggage) in my poor standard under powered 2.5DT returned 32 mpg on the motorway (and that was by brim to brim, not by the electricky confugulator).

A Powerbox tricks the Engine ECM/Injector system to suppling more fuel for more power, it may decrease fuel supply on over run, but bearing in mind that most injection systems these day cut totally the fuel supply on engine over run its not likely.

The best answer is, that the increased power allows increased acceleration to a given speed, allowing the throttle to be returned to a cruising position sooner.

Simon, a question for you:

How long at the vast saving of (lets be generous 0.4 mpg) is it going to take you to recoup the the cost of the Powerbox (350.00 approx)???



Simon1975 said:
Anyway, argue with PSI:

"A PSI Powerbox provides a perfect command in Parallel with the original engine Management system increasing Performance (read: more fuel used) and in most cases (read: if your very very lucky) Ecomomy without Due stress on the engine and Thermal Overload."

www.psipowerbox.com
Click to expand...

Sales Bull SH*T












































Answer to question ^ ferkin years......:doh:......:behindsofa:


PS: Enjoy the extra power but don't praise the economy unless your getting an extra 5 mpg at least.......
 
Last edited:
Simon1975 said:
I'm afraid I do not agree with that. The way I drive the car is not full on by any means, and with that style of driving the fuel economy is better with the PSI installed.

e.g. Rather than having my foot to the floor in the past to struggle up an incline at 55mph, it now cruises up nicely without excess throttle.

I do however understand what you are saying.

But the PSI Powerbox is supposed to use the fuel more efficiently than the original set up, hence better preformance and fuel economy.

Anyway, argue with PSI:

"A PSI Powerbox provides a perfect command in Parallel with the original engine Management system increasing Performance and in most cases Ecomomy without Due stress on the engine and Thermal Overload."

www.psipowerbox.com
Click to expand...

And how does the PSI powerbox do this. By injecting more fuel or by injecting less fuel? It may well be a more refined and linier injection control with less stepping, but you cannot have more power without more fuel, it is not possible.
 
wammers said:
And how does the PSI powerbox do this. By injecting more fuel or by injecting less fuel? It may well be a more refined and linier injection control with less stepping, but you cannot have more power without more fuel, it is not possible.
Click to expand...


Agreed........QED
 
wammers said:
And how does the PSI powerbox do this. By injecting more fuel or by injecting less fuel? It may well be a more refined and linier injection control with less stepping, but you cannot have more power without more fuel, it is not possible.
Click to expand...

That statement is absolutely not true. Through improved control of the fuel/air mixture achieved by electronic fuel injection, modern engines are producing phenominal power output per litre compared to engine of the 60's and 70's and actually useing less fuel. Diesel engines are someway behind their petrol cousins in the development of the fuel injection systems whereas direct injection is a relatively new thing on petrol engines.
When I was playing with club level racing engines in the 70's, 100bhp per litre was the goal, the engines had narrow powerbands and were tempremental to say the least and 10 or 12mpg was not unusual:( These days 100bhp per litre engines can be seen in normal road going cars and motorbikes, they are not tempermental, have wide powerbands and use between a third and a quarter of the fuel to achieve the same power :D:D:D

Despite the losses introduced by catalytic "con" verters, improvements in combustion efficiency will continue to be made.
 
zzr1200 said:
Whoopee Dooo's, a whole 0.3 mpg increase (if your really lucky you may see 0.5 mpg), increased power requires increased fuel usage....as Warmers said.....SIMPLES...:eek:



I live in the flat lands of Essex but do escape to more hiller country, went on holiday to the south coast (3 adults, 2 kids and luggage) in my poor standard under powered 2.5DT returned 32 mpg on the motorway (and that was by brim to brim, not by the electricky confugulator).

A Powerbox tricks the Engine ECM/Injector system to suppling more fuel for more power, it may decrease fuel supply on over run, but bearing in mind that most injection systems these day cut totally the fuel supply on engine over run its not likely.

The best answer is, that the increased power allows increased acceleration to a given speed, allowing the throttle to be returned to a cruising position sooner.

Simon, a question for you:

How long at the vast saving of (lets be generous 0.4 mpg) is it going to take you to recoup the the cost of the Powerbox (350.00 approx)???





Sales Bull SH*T












































Answer to question ^ ferkin years......:doh:......:behindsofa:


PS: Enjoy the extra power but don't praise the economy unless your getting an extra 5 mpg at least.......
Click to expand...


If you look at my original post, I was merley saying that I was pleased that the car is now better to drive and that fuel economy has increased, thats all, no stress needed.

I know its popular for people to upgrade their diesels this way and thought it would be helpful for others to know this info.

It's not about recouping the £305 spent on the PSI unit as such, it makes the car much better to drive.

:)
 
Simon1975 said:
If you look at my original post, I was merley saying that I was pleased that the car is now better to drive and that fuel economy has increased, thats all, no stress needed.

I know its popular for people to upgrade their diesels this way and thought it would be helpful for others to know this info.

It's not about recouping the £305 spent on the PSI unit as such, it makes the car much better to drive.

:)
Click to expand...

Absolutely right:D:D:D:D:D:D:D:D
 
Simon1975 said:
If you look at my original post, I was merley saying that I was pleased that the car is now better to drive and that fuel economy has increased, thats all, no stress needed.

I know its popular for people to upgrade their diesels this way and thought it would be helpful for others to know this info.

It's not about recouping the £305 spent on the PSI unit as such, it makes the car much better to drive.

:)
Click to expand...

Theres no stress at all, I would consider fitting a Powerbox to mine but I would want to try one first, after all its only "plug n play" power increase.

Let face it if we were after economy we wouldn't be driving Range Rovers, but 0.3 mpg is just the difference between having a fart with the wind or against it, nowt else.....;)
 
Last edited:
zzr1200 said:
Whoopee Dooo's, a whole 0.3 mpg increase (if your really lucky you may see 0.5 mpg), increased power requires increased fuel usage....as Warmers said.....SIMPLES...:eek:



I live in the flat lands of Essex but do escape to more hiller country, went on holiday to the south coast (3 adults, 2 kids and luggage) in my poor standard under powered 2.5DT returned 32 mpg on the motorway (and that was by brim to brim, not by the electricky confugulator).

A Powerbox tricks the Engine ECM/Injector system to suppling more fuel for more power, it may decrease fuel supply on over run, but bearing in mind that most injection systems these day cut totally the fuel supply on engine over run its not likely.

The best answer is, that the increased power allows increased acceleration to a given speed, allowing the throttle to be returned to a cruising position sooner.

Simon, a question for you:

How long at the vast saving of (lets be generous 0.4 mpg) is it going to take you to recoup the the cost of the Powerbox (350.00 approx)???





Sales Bull SH*T












































Answer to question ^ ferkin years......:doh:......:behindsofa:


PS: Enjoy the extra power but don't praise the economy unless your getting an extra 5 mpg at least.......
Click to expand...

why dont you just get on with your life and leave the people who have fitted powerboxes to get on with theirs,its a personal judgement as to what and why we do what we want to our own vehicles.
 
zzr1200 said:
Theres no stress at all, I would consider fitting a Powerbox to mine but I would want to try one first, after all its only "plug n play" power increase.

Let face it if we were after economy we wouldn't be driving Range Rovers, but 0.3 mpg is just the difference between having a fart with the wind or against it, nowt else.....;)
Click to expand...


Yeah its a small increase, and it may still rise, and I think it will.

But the main point is, that according to the cars computer, it has not decreased.

Hence, happy with power and the added bonus of increased fuel economy.

And I think that is important info for those looking at a diesel chip/box.
 
The improvements in fuel economy with a chip are long established and proven.

If you spend a bit of time doing the research you will find that yes, the power (or more specifically torque) is increased by 'dumping' in more fuel but the biggest gains are seen to counteract flatspots in the standard fuel map put there deliberately for emission reasons. The fuel economy gains are not the primary aim but a welcome side effect, more noticeable in autos, brought about by the car changing up earlier and kicking down less often as it is getting more torque to propel the car. Fuel consumption is directly related to revs, fuel economy revs and gearing, the earlier an engine has the torque to pull a higher gear the earlier it can change up and drop the revs. Once you've reached cruising speed the governor will reduce the injected fuel and there will be little difference between chipped/non chipped.
To get improvements in economy in a manual you will need to short shift. If you drive a chipped diesel like you stole it you will get worse fuel economy than a standard one driven the same way (you'll just get there quicker :) )

The same economy gains are found in the petrol V8 by a change of cam to a torque tuned cam which does exactly as above, changes up earlier and kicks down less often.

As for the 0.3mpg improvement, Simon, am I correct in that you didn't reset the fuel computer and that your long term average has improved by 0.3mpg rather than tank to tank. If not well I suppose its normal enough to drive it on a bit with the novelty of your P38 actually accelerating :) I'd expect it to settle down at about 2mpg tank to tank.
 
SpudH said:
The improvements in fuel economy with a chip are long established and proven.

If you spend a bit of time doing the research you will find that yes, the power (or more specifically torque) is increased by 'dumping' in more fuel but the biggest gains are seen to counteract flatspots in the standard fuel map put there deliberately for emission reasons. The fuel economy gains are not the primary aim but a welcome side effect, more noticeable in autos, brought about by the car changing up earlier and kicking down less often as it is getting more torque to propel the car. Fuel consumption is directly related to revs, fuel economy revs and gearing, the earlier an engine has the torque to pull a higher gear the earlier it can change up and drop the revs. Once you've reached cruising speed the governor will reduce the injected fuel and there will be little difference between chipped/non chipped.
To get improvements in economy in a manual you will need to short shift. If you drive a chipped diesel like you stole it you will get worse fuel economy than a standard one driven the same way (you'll just get there quicker :) )

The same economy gains are found in the petrol V8 by a change of cam to a torque tuned cam which does exactly as above, changes up earlier and kicks down less often.

As for the 0.3mpg improvement, Simon, am I correct in that you didn't reset the fuel computer and that your long term average has improved by 0.3mpg rather than tank to tank. If not well I suppose its normal enough to drive it on a bit with the novelty of your P38 actually accelerating :) I'd expect it to settle down at about 2mpg tank to tank.
Click to expand...

I never reset the computer, it was reset when I bought it about 2000 miles ago. It was saying put at 27.7 but has slowly risen to 28 over the last 300-400 miles since adding the PSI.

I do not even know how to reset the thing, I must read about that.
 
Mine is a manual and that's very true, when I'm driving steady away, which is most of the time in this car, I do short shift just to keep it in the power, over 2k-3k revs.
 
Simon1975 said:
I never reset the computer, it was reset when I bought it about 2000 miles ago. It was saying put at 27.7 but has slowly risen to 28 over the last 300-400 miles since adding the PSI.

I do not even know how to reset the thing, I must read about that.
Click to expand...


To reset the average mpg, scroll through the display by repeatedly pressing the lower button on the left stalk until it shows Trip 2, then press and hold the button until it shows zero. All the figures for average mpg, speed etc will the be reset and will show "Computing mpg" Computing Range, Computing Average Speed until you have covered a few miles.:D

Sad person that I am, I reset mine each tank full and use the average mpg display to amuse myself by sqeezing the figure up as much as I can;)
 
Datatek said:
To reset the average mpg, scroll through the display by repeatedly pressing the lower button on the left stalk until it shows Trip 2, then press and hold the button until it shows zero. All the figures for average mpg, speed etc will the be reset and will show "Computing mpg" Computing Range, Computing Average Speed until you have covered a few miles.:D

Sad person that I am, I reset mine each tank full and use the average mpg display to amuse myself by sqeezing the figure up as much as I can;)
Click to expand...

Cheers for that, I will have a look when I get a chance, its the Mrs car, hence I have not been in it that much yet.
 
Interesting opinions,and directly related to my queries on the same subject posted last week.

I think I will invest in the PSI Powerbox for that little bit of extra oomph when overtaking etc...My grateful thanks to all you fellas for helping me make up my mind!
Cheers One & All!!
 
Simon1975 said:
Cheers for that, I will have a look when I get a chance, its the Mrs car, hence I have not been in it that much yet.
Click to expand...


Since I bought mine I haven't been able to get the Mrs out of it either, I just get to clean it and repair it:doh::doh::doh:
 
Datatek said:
To reset the average mpg, scroll through the
Sad person that I am, I reset mine each tank full and use the average mpg display to amuse myself by sqeezing the figure up as much as I can;)
Click to expand...

I'm glad I'm not the only one who does this
 
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