Cruising Speed?

[Pudsey Bear]

Foot right off the gas going down hill until the speed drops too far, then gently gas it again, see a red light off the gas, see a queue off the gas, read the road, try not to brake or worse still stop.

 

[SimonM]

A little while ago France decided to reduce their 90kph limits down to 80kph (56 to 50mph) in order to reduce pollution, or road deaths, or something Gallic. Then the truckers were all up in arms saying they ran most efficiently at 90, and now many of those 80 limits have been rescinded and are back at 90.

 

[cheyenne]

The 56mph is a hell of a myth, economy comes from how a vehicle is driven and it's shape, a Luton van may run at a totally different economical speed to a Fiesta car.

hi pudsy bear . how come

It was part of the European triumvirate of speed standards for years, Kev. Manufacturers were required to state fuel consumption at a constant 90kmh, at 120kmh,, and, IIRC, an urban cycle of 50kmh. The measurements have been changed over the years and now take into account hybrids and electric vehicles and the odd diesel emissions scam (VW were very wrong in their actions...)

Steve

hi guys . yes your right hgv's speed limit is 60mph BUT are governed at 56mph . had many a restrictor go belly up so took advantage & drive up to 60mph . i was in pulled in the layby enroute to barrow for checks not over weight but looked at the tachograph & said get the restrictor sorted but never got charged for speeding even though the police was there . they brought out the taco's in the UK in the early eighties .cheyenne

 

[cheyenne]

A little while ago France decided to reduce their 90kph limits down to 80kph (56 to 50mph) in order to reduce pollution, or road deaths, or something Gallic. Then the truckers were all up in arms saying they ran most efficiently at 90, and now many of those 80 limits have been rescinded and are back at 90.

hi simon. yes they have but its not all departments have gone back to the old limits .cheyenne

 

[Pudsey Bear]

hi pudsy bear . how come



Please read my post #39

 

[Ardachaidh]

I cruise at whatever speed I feel most comfortable with, given road conditions, safety, etc. Towing a trailer we are restricted anyway. On the horrendous motorways in England on the way to Portsmouth I tend to either cruise at between 56 and 60 or tuck in behind an hgv - leaving sufficient space for another. Never manage more than 33mpg, usually nearer 30 in the Ducato.

 

[Pudsey Bear]

Not bad mpg when towing.

 

[davef]

My '91 Transit lwb 2.5 non turbo is happiest at 40-45 mph. If pushed it will get up to 50-55mph, but too happily unless down hill - I did see 60 once on a long downhill, but it sounded a bit frantic! You get into a different more relaxed state of mind at these slow speeds and do see a lot more, but we have avoided motorways. Regardless of types of roads and whether pushed or ambling along it gets 32-36mpg which as it weighs in at 2.8t I am quite pleased with. Be nicer to have a bit more power than the the 70 horses for going uphill though.

 

[Pudsey Bear]

And zero electronics too unless you have a radio in it great old Trannys, I had a couple of smiley front ones, I keep seeing one of my old ones trundling around Bradford now and then, rusty as hell but still going on.

Liz says we should look at getting and old van but it would have to be a tranny, R reg with turbo at least..

 

[trevskoda]

And zero electronics too unless you have a radio in it great old Trannys, I had a couple of smiley front ones, I keep seeing one of my old ones trundling around Bradford now and then, rusty as hell but still going on.

Liz says we should look at getting and old van but it would have to be a tranny, R reg with turbo at least..

The old engine was about the only thing good on a tranny, lots of folk maranise them with intercooler kits for boats, i have a kit and engine here to build.

 

[Pudsey Bear]

The only thing that bothered me was you were so close to the dash compared with my cars, but it made a for a shorter van overall.

 

[Rumour]

We are in France and I love the 80kph speed limits. I can tootle along without holding others up. We are currently in Dreux, after visiting Le Mont Saint Michel and Arromanches for D-Day. So far, around 28 mpg. Fully loaded with water, food and whisky! Oh, and my good lady, the bad one couldn't get away this week. Yep, 80k on cruise control, through the beautiful French countryside. I couldn't be happier.

 

[TJBi]

We are in France and I love the 80kph speed limits. I can tootle along without holding others up. We are currently in Dreux, after visiting Le Mont Saint Michel and Arromanches for D-Day. So far, around 28 mpg. Fully loaded with water, food and whisky! Oh, and my good lady, the bad one couldn't get away this week. Yep, 80k on cruise control, through the beautiful French countryside. I couldn't be happier.

I find the 80km/h speed limit a mite slow and it also makes it difficult to maintain cruise control in 6th gear if one encounters even moderate hills, whereas 90km/h enables one to cope with a greater range of inclines in 6th gear.

 

[maingate]

Maybe my Renault based van had higher gear ratios but I rarely got into 6th gear. It was basically used on motorways and the odd (quiet) dual carriageway. I felt that at anything under 60 mph the rpm was too low and putting a strain on the gearbox.

 

[Pudsey Bear]

Same on our Fiesta, 30mph = 3rd gear, need to be over 40mph for 4th, and 5th only on level roads, lower gears = higher revs which = more fumes.

 

[Okta]

lower gears = higher revs which = more fumes.

Is that strictly true? Revs are part of the equation but I think the amount of throttle used also has a big bearing on the fumes. i.e. Being in too high a high gear with the right foot hard on the floor will use more fuel and create more fumes than dropping a gear.

Same on our Fiesta, 30mph = 3rd gear, need to be over 40mph for 4th

My VW Up is exactly the same.

 

[Pudsey Bear]

Is that strictly true? Revs are part of the equation but I think the amount of throttle used also has a big bearing on the fumes. i.e. Being in too high a high gear with the right foot hard on the floor will use more fuel and create more fumes than dropping a gear.

Not entirely sure but it seems reasonable that if your engine is spinning faster it will use more fuel and create more exhaust, but bearing in mind what you say, it might burn cleaner so could be less polluting.

Dunno.

 

[Scotia]

I'm no lookin forward to getting old if that's the worry you are all getting, what's next the weather?

 

[Okta]

Not entirely sure but it seems reasonable that if your engine is spinning faster it will use more fuel and create more exhaust, but bearing in mind what you say, it might burn cleaner so could be less polluting.

Dunno.

I am not entirely sure either but I do know that the amount of fuel injected depends on how much throttle is used as well as the revs.
Dunno Either. Is there a thermodynamics engineer on the forum?

 

[Okta]

I'm no lookin forward to getting old if that's the worry you are all getting, what's next the weather?

Yep, the weather is affected by pollution too. They now have to wear masks in the USA because Canada is burning too much wood. Getting old helps we can leave the problem for others to sort out.