Fuel efficiency

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dubbedup67

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Here's a question.

What's the best way to make a bus more fuel efficient?

I'm currently running a 1600tp on a stock box in my 68 and a recent trip to Cornwall ended up costing a fortune in fuel!
I think we averaged about 18-20 mpg.

Could it be I have running issues or is this normal?
Is there a way to make it more fuel efficient?
 
Should at least be able to maintain 25mpg+ on a long run.

Lots of factors here though, crusing speed? RPM? Roofrack? Wind Direction?Hills?

Although it sounds like your bus probably needs a bit of time on a rolling road to get the jetting right to reduce fuel consumption.

You can get better efficiency with dual carbs (usually single barrel such as Weber 34 ICT's are the most efficient), upping your fuel economy to 28-30 mpg ish.

Sent from my Siswoo C55 using Tapatalk
 
rlepecha said:
Should at least be able to maintain 25mpg+ on a long run.

Lots of factors here though, crusing speed? RPM? Roofrack? Wind Direction?Hills?

Although it sounds like your bus probably needs a bit of time on a rolling road to get the jetting right to reduce fuel consumption.

You can get better efficiency with dual carbs (usually single barrel such as Weber 34 ICT's are the most efficient), upping your fuel economy to 28-30 mpg ish.

Sent from my Siswoo C55 using Tapatalk

Hmmm well we were fully loaded with stuff for the week,cruised at about 55/60 and we don't have a roof rack.the hills were an issue when we got down there.

I was wondering that but I wouldn't know where to start enquiring.
So does it sound like it's just my van has running issues?
 
I had this issue. I was getting 12 by my reckoning MPH. That was cutting around Wales. I have a stock 1600 TP. I am currently running a 009 dizzy which will drop your MPG by 4 or 5 miles I was also running the wrong fuel rod.

Changed fuel rod and MPG much better around 18 MPG. Wales is hilly.

If you were loaded this will drop your MPG massively. More weight more fuel. These things are not airo dynamic it's like pushing a brick through the air. Many on here say 25 is the best they get so I wouldn't get overly worried.
 
There are many different factors - the only way you're going to know if your current setup is running at maximum efficiency is to get it to a specialist and have it checked / setup on a rolling road. Unless you're getting extremely poor mpg (which it doesn't sound as though you are), it is going to be guesswork as to there being a problem or not.
 
I'd start keeping a fuel log and noting it down every time you fill up.

After a while you'll get a good view of what mpg you're getting and then know if it's a problem.

My 1641 sp with a 123 ignition does about 22mpg just running around
 
dubbedup67 said:
Here's a question.

What's the best way to make a bus more fuel efficient?

I'm currently running a 1600tp on a stock box in my 68 and a recent trip to Cornwall ended up costing a fortune in fuel!
I think we averaged about 18-20 mpg.

Could it be I have running issues or is this normal?
Is there a way to make it more fuel efficient?

Your 18-20 mpg is about right. They only did about 22mpg when brand new.



I'm currently running a stroker motor with twin 40 IDFs, and I can get around 36mpg on a long run at around 55-60mph as I'm sitting on the idle circuits only.
If I drive it around more enthusiastically and use all the rev range it drops to 10-12mpg.
 
sparkywig said:
dubbedup67 said:
Here's a question.

What's the best way to make a bus more fuel efficient?

I'm currently running a 1600tp on a stock box in my 68 and a recent trip to Cornwall ended up costing a fortune in fuel!
I think we averaged about 18-20 mpg.

Could it be I have running issues or is this normal?
Is there a way to make it more fuel efficient?

Your 18-20 mpg is about right. They only did about 22mpg when brand new.




I'm currently running a stroker motor with twin 40 IDFs, and I can get around 36mpg on a long run at around 55-60mph as I'm sitting on the idle circuits only.
If I drive it around more enthusiastically and use all the rev range it drops to 10-12mpg.

Stock motors are **** on fuel, you gotta think your really working that little 1600 to lug a boxy and heavy fully loaded bus. In a bug they are good but a bug is 680kg or so? A bus is a lot more. My 2110 stroker with 48 IDF's does about 30 mpg on a run but mines a more highly strung engine than Sparkywig's, we both do have high ratio gearboxes which also helps. However as he also if you nail it the mpg does drop, I drove home from my girlfriends parents 1 night which is 11 miles to mine. I was pulling 7000 rpm in every gear and used nearly 1/2 a tank.
 
Love these conversations, wish I had a stroker motor. :lol: :lol:
I thought I was doing well at 20/21 mpg and then had the timing done ,
now down to 24/25 mpg , stock engine and always have major weight.
I also never exceed 60 mph , so that might also help.

J & P
:D :D :D
 
Make sure your vac advance on the dissy is working correctly. It's primarily an economy device because it provides extra spark advance on light throttle. Running that much advance on full throttle would cause detonation/pinking.
 
1 thing I found that out my mpg up with my old 1600 was a rebuilt carb, not just a kit from Machine 7 rebuild but a completely rebuilt 1 from Cogbox. Cost me £200 BUT it transformed my vans fuel efficiently, performance and smoothness.
 
22mpg sounds about right for 1600 engine. I 've driven all over Europe with about that figure. Going above 65 mpg drastically increases fuel consumption. A weber progressive carb helps on the hills - with stock solex I was down to second gear on steep hills - ( new engine) which again increases consumption. Heat and temperature also a factor - driving in 25+ degrees makes the engine work harder (e.g. in Spain) 8)
My bus is stock - I imagine lowered would offer less wind resistance?
 

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