Speed limiters
Submitted: Wednesday, Jan 23, 2008 at 23:48
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Steve from Top End Explorer Tours
On my recent trip I did some experiments with speed verses fuel economy.
I found that at 90 kph I achieved 900 km on 132 litres of diesel, this is with a roof rack with 2 tyres on it and a camper trailer at about 1 tonne.
this was my best effort, at 100 + I couldn't get 600 ks out of two tanks.
Now I have 4 trucks and the Diesel is $1.60 in
Jabiru and I don't see it coming down any time soon.
So with no roof rack and a 90 kph limit on my cars I believe I could save money on fuel, as my fuel is about $7500 a month last year at $1.45 per litre.
Before people say 90 kph on the hwy will only frustrate other drivers these cars only do 50 km to the Jim Jim turn off and back and the rest is dirt road and 4wd terrain.
Doe's any one know of a speed limiter I could use on my cars as none of my cars achieved any where near this economy last year.
Cheers Steve
Reply By: Willem - Wednesday, Jan 23, 2008 at 23:56
Wednesday, Jan 23, 2008 at 23:56
Yer.....a sharp instrument attached to the accelerator cable that prics the driver's leg when they get too excited
LOL
Good to see that you had a good trip and that youhad no dramas along the way.
I like sitting on 85km/h and get up to 8km/l sometimes with the 600kg trailer on the back
Cheers
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Follow Up By: Steve from Top End Explorer Tours - Thursday, Jan 24, 2008 at 00:04
Thursday, Jan 24, 2008 at 00:04
Hey Willem
Its easy to get exited when someone else is paying for the fuel.
One of my old bosses had a device that beeped when you hit 100 but they were easy to find and disconnect.
Yeah we had a ball just wish we had more time.
Cheers Steve.
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Reply By: Member - Doug T (FNQ) - Thursday, Jan 24, 2008 at 05:54
Thursday, Jan 24, 2008 at 05:54
Steve
you could give this systen a look
GPS Vehicle Tracking Systems
.
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Follow Up By: Robin Miller - Thursday, Jan 24, 2008 at 07:56
Thursday, Jan 24, 2008 at 07:56
Hi Steve
There are a number of ways of sensing speed and operating a relay which then shuts something down or controls a flashing light - these include simple kits from jaycar and some gps outputs however i would not reccomend anything which shuts down engine over a certain speed as someone where will get cauht out overtaking etc.
As fuel use only goes up at under the square of the speed increase you wouldn't save more than 15% by going at 90 instead of 100.
The reaL issue is perhaps hard acceleration and driving much faster.
A relatively simple answer to this is to change the accelerator cable position such that you simple can't get full throttle.
Often a five minute job as on many cars its just some lock nuts.
Robin Miller
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Follow Up By: Member - Kiwi Kia - Thursday, Jan 24, 2008 at 08:23
Thursday, Jan 24, 2008 at 08:23
Hi Robin, ........and some lock wire on the back nut. :-))
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Follow Up By: Robin Miller - Thursday, Jan 24, 2008 at 08:35
Thursday, Jan 24, 2008 at 08:35
Hi Kiwi
For sure , I use black nail polish myself - woops before I get accused of things I should state that this is common in the electronics industry - woops I should explain further , I mean the use of nail polish to restrict nut movements is common.
I can't explain why I use black though !
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Follow Up By: Member - Kiwi Kia - Thursday, Jan 24, 2008 at 08:41
Thursday, Jan 24, 2008 at 08:41
Yeah, good one Robin, black isn't often used on ome pc bds. Electroclean or similar takes it off but it takes all the component colours/numbers off too ! :-))
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Follow Up By: furph - Thursday, Jan 24, 2008 at 08:50
Thursday, Jan 24, 2008 at 08:50
All diesels have the engine speed controlled by a govenor controlled by the stops on top of the injection pump.
The pump max. output is controlled by the threaded stud behind the pump body.
Unscrewing this out will reduce (ie. "derate") the pump output, combining the adjustment of both will give the desired result.
(this stud has a sleeve spot welded to it to prevent it being screwed further in which will cause over fuelling and engine damage)
furph
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Follow Up By: Member - Doug T (FNQ) - Thursday, Jan 24, 2008 at 08:53
Thursday, Jan 24, 2008 at 08:53
Steve
I might add that any of the other methods posted here could be a danger if in an emergeny and had to get to ..ie a hospital in a hurry with a passenger could be danger, at least with the gps monitoring system the vehicle is still capable of high speed, under normal conditions you have knowledge of whats going on.
Robin Miller mentioned problems overtaking, The Truckies have been forced into that situation by stupid knee-jerk reactions of the bloody pollies.
.
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Follow Up By: DIO - Thursday, Jan 24, 2008 at 10:06
Thursday, Jan 24, 2008 at 10:06
Now c'mon Doug, how can you say the 'truckies were forced into that position by pollies'? I always thought that within the laws of motion, for every action there was a reaction, ie. foot down on accelerator, speed increases. If vehicle is restricted to a given speed, then that's as fast as it will travel (more or less). Speed restrictors were introduced because many of these transport drivers just couldn't be trusted to do the 'right thing', plus many owners wanted to reduce wear and tear etc on their rigs so they were happy to their drivers thus restricted. The problem, if that's what you think it is, was a direct result of many within industry 'not playing ball'.
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Follow Up By: Member - Doug T (FNQ) - Thursday, Jan 24, 2008 at 11:43
Thursday, Jan 24, 2008 at 11:43
DIO
Seems you have a short memory or maybe you you were still in the womb when the truck/bus accident happened near Kempsey,it was no time at all the law was rushed through parliment, If your not involved in the transport industry or never driven a truck/Roadtrain then I don't think your qualified to comment, having said I will not be drawn into useless arguments on this subject with someone who knows stuff all about trucks.
.
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Follow Up By: Dave(NSW) - Thursday, Jan 24, 2008 at 17:18
Thursday, Jan 24, 2008 at 17:18
Dio
Doug is 100% right it was a knee jerk reaction to a major accident a Clybucca.A speed limiter only works properly on a flat road ,If a loaded speed limited truck is going down
hill it is possible for it to hit speeds of 120/130 easily. If speed limiters were introduced because trucks wear doing the wrong thing then why don't they restrict car speeds as more car drivers seem to get caught speeding each year.
Dave....
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Follow Up By: ob - Thursday, Jan 24, 2008 at 18:09
Thursday, Jan 24, 2008 at 18:09
driving across the Nullabor sitting on about 100kph and passed by a semi like I was standing still. no hills out there last time I looked
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Follow Up By: Dave(NSW) - Thursday, Jan 24, 2008 at 21:11
Thursday, Jan 24, 2008 at 21:11
Don't remember anyone saying all trucks were speed limited!!
Dave..
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Reply By: brushmarx - Thursday, Jan 24, 2008 at 10:34
Thursday, Jan 24, 2008 at 10:34
Hi Steve
The old Datsun 180B's used a height adjustable bolt through the floor directly under the accelerator pedal. Wound down to floor added an extra 25kph.
You could fit similar to these real cheap, and it would also stop hard acceleration as
well as top speed.
Just screw on a Dick Smith "black box" (any type of electrical looking thing), and fit a wire or two onto the bolt, pedal, and earth, and tell your drivers it's a monitor to prevent ancillary adjustment of the limiter, but can be over ridden in cases of emergency with a few turns of a spanner.
All up, probably $20 or so.
Cheers
Ian
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Reply By: tdv - Thursday, Jan 24, 2008 at 10:46
Thursday, Jan 24, 2008 at 10:46
What about no gismo at all. Just offer a pay incentive? If their fuel bill is below a certain level they get bonus in their wages. You could go halves in the savings and keep the staff happy?
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Reply By: rockpiglet - Thursday, Jan 24, 2008 at 11:18
Thursday, Jan 24, 2008 at 11:18
Hi Stev
The best I have seen are for heavy vehicles like Aussie Posts. GPS/ Sat tracking at all times. If the driver exceeds speed limit I think it's for 5sec, a buzzer sounds, if they do it 3 times the phone rings and they are talking to someone about it. Mind you they get a call if their sitting still as
well.
Expensive system but you know where all your vehicles are at all times as you can watch it on your computer. Great for any liability regarding safety, insurance etc.
There is also a memory stick you can buy and put in vehicles,(like under the
seat) when you download to the computer it shows times speeds etc.
If your doing set runs, work out worst fuel use, best fuel use and if the drivers comes in under the average they get a bonus. It's an incentive for them to drive for fuel economy and you still save.
I have drivers for example who will do Syd > Bris return and use 100l more than another driver. So the one who saves fuel gets the cream jobs and a bonus, it doesn't take long for the rest to work it out.
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Reply By: Gerhardp1 - Thursday, Jan 24, 2008 at 11:58
Thursday, Jan 24, 2008 at 11:58
I'm not sure you are comparing apples with apples.
By doing 90, you extend range from 600ks to 900ks, implying that you travel 900ks at cruising speed.
Then you say the max distance you can go at 90kph is for the 50ks to the turnoff. So in a return trip, only 100 ks is at cruising speed.
It may not be worth stuffing around with expensive/frustrating/limiting cures to save fuel on such a small part of the trip.
You'd probably get more variation from headwind/no headwind on that stretch than dropping 10ks.
If you regularly travel huge distances at cruise, 90k might send you to sleep :) then it wouldn't matter how much fule you'd saved.
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Follow Up By: Steve from Top End Explorer Tours - Thursday, Jan 24, 2008 at 14:45
Thursday, Jan 24, 2008 at 14:45
At 90 kph I had a range of 330km with the sub tank filled to the brim,
At 100kph my range was 270km with the sub filled to the Brim.
Last year the cars had a range of 230 km with the cars filled to the brim, the cars would come
home with the tanks changed to the main tank, the return journey for the tour is 230 km no more no less.
This would suggest the cars were driven at speed.
I will look closely at Furphs idea and speed limit to 100, as coaches are speed limited to this.
This will not be happening to the bosses car, hopefully a 6cl TD GXL soon.
Cheers Steve
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Reply By: Moose - Thursday, Jan 24, 2008 at 14:33
Thursday, Jan 24, 2008 at 14:33
G'day Steve
I think tdv is on the money here. The drivers are the key to reducing your fuel costs. Have you had a team meeting to discuss how you and they can benefit from reduced fuel consumption? If it is in their best interest (financially or via some other reward method) I reckon you will achieve the desired outcome.
Manually limiting the top speed could potentially be dangerous and you could leave yourself open to legal consequences in the event of something going wrong.
Cheers from the Moose
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Follow Up By: Steve from Top End Explorer Tours - Thursday, Jan 24, 2008 at 14:49
Thursday, Jan 24, 2008 at 14:49
Trucks and Coaches are speed limited, so I can't see why speed limiting a car is different , having said that I will check with MVR.
Cheers Steve.
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Follow Up By: Mike Harding - Thursday, Jan 24, 2008 at 17:37
Thursday, Jan 24, 2008 at 17:37
Stick or carrot? Basic psychology, the experience of others and my own experience of employing and managing people over the past 25 years suggests the carrot is the better option.
Mike Harding
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Reply By: Member - Mottleman (NSW) - Thursday, Jan 24, 2008 at 14:45
Thursday, Jan 24, 2008 at 14:45
Gday Steve
I wonder of there may have been other variables contributing to the different fuel useage figures as well as the speed drop.
I would be happy to be wrong but I'd be surprised if you got a 50% (600 to 900) improvement from just 10km/h drop on its own.
Any thoughts?
cheers
John
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Follow Up By: Steve from Top End Explorer Tours - Thursday, Jan 24, 2008 at 15:00
Thursday, Jan 24, 2008 at 15:00
I fuelled up at
Marla to the brim, I drove out to the rock, around the rock and back to the Stuart Hwy at 90 kph the low fuel light came on at 897 km, the next time with the same amount of fuel EG: filled to the brim I drove at 95 to 100 kph and the low fuel light came on at 850 km, At 100 to 115 kph I was flat out getting 600 km.
As I said I was experimenting.
Cheers Steve.
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Follow Up By: Mike Harding - Thursday, Jan 24, 2008 at 17:40
Thursday, Jan 24, 2008 at 17:40
And the wind speed and direction relative to the vehicle on the two separate occasions was...?
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Follow Up By: Steve from Top End Explorer Tours - Thursday, Jan 24, 2008 at 18:18
Thursday, Jan 24, 2008 at 18:18
Mike I was on holidays taking notes with pen and paper, I simply made some comparison's.
I was just asking for ideas on speed limiting my cars, no more no less,
As for the carrots well I offered incentives to my staff last year in the form of a Xmas bonus and only one came up trumps, although ironically he used the most amount of fuel.
Cheers Steve.
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Follow Up By: Mike Harding - Thursday, Jan 24, 2008 at 18:32
Thursday, Jan 24, 2008 at 18:32
Unless you take all the variable into account especially the big ones (and we won't even discuss "uncertainty of measurement") any test over two trials is meaningless - if you were to perform this same drive 30 or 40 times across the year you would average the variables to a sensible level and would _probably_ have a result which you could be confident was within about 10% of accurate - probably...? Your test of varying the speed by 10kph only needs small changes in wind direction or velocity to make it invalid.
Mike Harding
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Follow Up By: stevesub - Friday, Jan 25, 2008 at 01:54
Friday, Jan 25, 2008 at 01:54
I once did MLB to
Brisbane up the Newell a few years ago. One tank at 90kph and one tank at 100kph. From memory, there was about a 15% increase in fuel consumption at 100kph when compared with 90kph
It was is a non-turbo 1HZ troopy, no roof rack and not towing.
Terrain and wind were the same for both tanks and overall the trip would have taken from memory 2 hrs longer at 90kph but saved 15% of fuel. We also know that the Troopy really drinks the fuel at 110kph. Over the years we have got a low of 600km and a high of 750km from a tank of fuel (85L) but it all depends on the speed of travel.
Only problem on the Newell is that everyone (incl trucks) seemed to be going at 110kph+ which is higher than we really want to travel at (100kph)
Stevesub
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Reply By: Bonz (Vic) - Saturday, Jan 26, 2008 at 14:41
Saturday, Jan 26, 2008 at 14:41
yea but ...... 90 kph on the hwy will only frustrate other drivers
hahahahaha Great to see you got back home safely Steve, the family are all OK down here, Paul is on the cusp of enetering the Army for his gap year and all is not too bad.
Have to get up there one time when we can go to JimJim falls with you rather than a flight over it (which was fantastic too), although the Ubirr that you took us to see, the isolation and lack of crowds was (and still is) the highlight of our NT holiday.
And I promise I will sit on 90kmh mate
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