How about slipstreaming?

thunderb0110cks
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How about slipstreaming?

Postby thunderb0110cks » Thu Feb 09, 2012 8:04 am

Hi. New to the forum.

I was on the M4 early this morning sitting at a comfortable fuel efficient 55mph and a lorry passed me doing about 60mph and a thought struck me. Would it be more efficient for me to continue sitting at 55 or to tuck in behind this lorry and slipstream at 60?

Im driving a 2000 Mondeo 2.0 diesel estate and im always looking to better my average of 45mpg.

Cheers fellas.

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frv
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Re: How about slipstreaming?

Postby frv » Thu Feb 09, 2012 9:17 am

Hi there and welcome to the forum (great name by the way ;) )

If you don't have to increase your speed too much it's probably worthwhile although drafting at 55 would probably be better.
What I would do is tag along with the lorry for a bit until he catches up with a slower one and then pull in behind that one :)
Obviously you have to be at a safe distance (at least 2 seconds) as we wouldn't condone Nascar style slip streaming on this forum :roll: :lol:

It definitely has a beneficial effect on FE as I have an Ultra-Gauge which give me loads of great information including Instantaneous MPG and Engine Load and if I draft a lorry it goes up maybe 10 - to 20 mpg.
'15 Audi A3 Sportback SE CoD S-Tronic - 5+ year average 55+mpg
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(Retired) '06 Honda FR-V 2.2 i-CTDi - Best/longest tank: 67.92mpg (+51.6%) / 815.5 miles.

thunderb0110cks
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Joined: Thu Feb 09, 2012 7:47 am

Re: How about slipstreaming?

Postby thunderb0110cks » Thu Feb 09, 2012 10:07 am

Good to know, cheers frv.
Couldnt see why it wouldnt save fuel, you had the same principal in your head as i did about drafting as per racing tactics as the vehicle infront breaks the air and leaves the car behind not having to withstand as much air resistance and drag so uses less energy to power the car.............. or some crap like that!

Whats this ultra gauge? Factory fitted or after market?

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frv
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Re: How about slipstreaming?

Postby frv » Thu Feb 09, 2012 10:32 am

Spot on!

The Ultra-Gauge is an after market gauge you plug in your car's OBDii socket.

I got mine from the States. There are other gauges, like the ScanGauge but they are a bit pricey (and geeky :geek: ) at about £130.

http://www.ultra-gauge.com/ultragauge/index.htm

Karl started a thread on the Ultra-Gauge here:
http://www.hypermiler.co.uk/forum/viewt ... f=17&t=573

and here's my thoughts about it here:
http://www.hypermiler.co.uk/forum/viewt ... f=17&t=503
'15 Audi A3 Sportback SE CoD S-Tronic - 5+ year average 55+mpg
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(Retired) '06 Honda FR-V 2.2 i-CTDi - Best/longest tank: 67.92mpg (+51.6%) / 815.5 miles.

thunderb0110cks
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Joined: Thu Feb 09, 2012 7:47 am

Re: How about slipstreaming?

Postby thunderb0110cks » Thu Feb 09, 2012 5:07 pm

Ill have to take a look at one of those. I aint got an mpg computer in the mondeo and could do with one.
At the mo im just using a good mpg calculator and data app on my phone. Its good but only really accurate if i fill up at exactly the same point on the fuel gauge on the car every time and thats hardly ever possible because i dont ever drive the same place for work every day and if i cant find a fuel station at that exact point on the gauge, its not exactly accurate. :roll:

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frv
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Re: How about slipstreaming?

Postby frv » Thu Feb 09, 2012 7:32 pm

Tricky!
Do you log your mpg?
I use Fuelly.com and a spreadsheet to track how I'm doing personally and compared to other people with the same car.
'15 Audi A3 Sportback SE CoD S-Tronic - 5+ year average 55+mpg
Image

(Retired) '06 Honda FR-V 2.2 i-CTDi - Best/longest tank: 67.92mpg (+51.6%) / 815.5 miles.

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Karl
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Re: How about slipstreaming?

Postby Karl » Fri Feb 17, 2012 10:49 am

Hi there - thunder and welcome to HM.

Slip streaming def has its advantages over speed. If I ever spot a coach then you can guarantee I'll be hitching a ride behind its wake.

An ultra gauge is a great addition to any car full stop. It gives you much more info than any OEM fuel computer can and will help you no end with your Hypermiling efforts.
2015 Skoda Octavia VRS Combi 2.0 TDI 184 DSG in Candy White - 50MPG and climbing

markc
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Re: How about slipstreaming?

Postby markc » Thu Jun 20, 2013 12:23 pm

The "Mythbusters" tested this, look here... http://www.youtube.com/watch?v=lttgT1XZ ... age#t=534s

It works well but you have to be very close (dangerously so?) to the lorry. They found an 11% improvement in fuel efficiency at 100ft and a 40% improvement at 10ft.

At 55mph you cover about 80ft per second so you need to be 160ft (2 secs) behind the lorry to be safe. Certainly the 10ft test looked scarily close :shock:

Cheers

Mark

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Re: How about slipstreaming?

Postby MikeMarsUK » Thu Jun 20, 2013 3:14 pm

There will be a benefit at 2secs, but it will be small. However the main benefit of being 2 or 3 seconds behind a HGV is really the effect on other drivers rather than the slipstream (they see the HGV and drive around you in the process), whereas if you were doing the same speed without a HGV ahead they're more likely to tailgate etc.
Audi A2 1.4 TDI w/6-speed gearbox. Best tank 87mpg, average of all tanks 75mpg. Fuelly ID is MMUK.

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tighterse
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Re: How about slipstreaming?

Postby tighterse » Thu Jun 20, 2013 5:29 pm

I notice this when towing a caravan. When I am passed by a heavy lorry I flash to let him know he is clear. When he pulls in a surge in both speed and the MPG gauge is immediate and continues until he well, maybe 100 + yards, in front of me. Then it is back to the mid 30s mpg sadly.
Kia Ceed 1.6 crdi isg Retired undefeated on 25,720 miles and 62.91 mpg overall

Now driving my second Sportage.

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