Over 60mpg at 80mph on cruise contol??

[NigelOBB]

You mean this bloke http://m.green.autoblog.com/2011/09/...uinness-recor/

That's to the extreme he's still driving though.. A US gallon is 3.785 litres so it in proper money he averaged about 54mpg..

[maintenanceman]

Does anybody also ponder on the average speed indicated. I know I think I'm driving faster than the average speed indicates especially on non-motorway driving with junctions and roundabouts pauses. Eg you feel you've driven close to 60 mph and it indicates 40something. Got to have some effect on mpg.

Whenever I get 'sad' about mpg I remember my old Nissan which struggled to do 20mpg. (I'll just wait for the V6/8 boys to tell me their worst!)

[T-Cut]

Originally Posted by maintenanceman

Does anybody also ponder on the average speed indicated. I know I think I'm driving faster than the average speed indicates especially on non-motorway driving with junctions and roundabouts pauses. Eg you feel you've driven close to 60 mph and it indicates 40something.

It's the average speed over the period since the last reset. Even a short stationary period pulls average speed down considerably and it takes a lot of continuous fast driving to bring it back to where you might expect. Generally, the average indicated will always be lower than you imagine. If you reset it while driving on a motorway say and then check the average after a 50 mile run, it will show what to expect more or (probably) less.

TC

[James.uk]

Yep, that's him... Wayne Gerdes... I remember him boasting online about tailgating Large vehicles as often as possible, only braking in emergencies, and spending as much time as humanly possible freewheeling..

One of the other forum members had a lift with him, and said he had never been so frightened in his life!!
...

[bassman]

Originally Posted by T-Cut

Yes, you're right. If you want to know how far every tank takes you, you're doing it right. Calibrating the OBD calculation is critical to this, but the calibration only represents the sort of driving you were doing when you generated the calibration data. So, you need a calibration set for each type of driving style you contend with. It's quite likely that a calibration based entirely on driving at say 80mph using cruise control would show that every time you drive that way your consumption figure is quite amazing - compared with the figures others quote for 'average' driving. At the end of the day, it all depends on what you mean by - - -.

As a matter of broader interest, what does the OBD say about your typical running temperature?

TC

Re your last point......Ive not got round to that yet, its been on my mind for a while, as although it always runs at 9o'clock, it takes a good 5 miles to get there...I was looking to do the stat mod, but was actually going to ask you, before doing this, if the increased pressure in the thermostat opening late has ever(in your opinion) caused any radiator bursts or the like, as I am talking about a 12 year old vehicle with almost 200k on the original radiator...

Ive studdied the OBD mpg for a while now, and have seen 10mph, on pulling out of the petrol station up the bank in second gear, and the 300mpg resetting the OBD at the top of a 4 mile downhill run....but Ive also noticed the difference in revs, between 3rd 4th and 5th gears....I lost concentration yesterday while talking to passengers, and found I'd travelled a mile in 3rd gear(flat urban road) which normally I would have taken in 5th gear........the difference...about 600rpm..........now doing that constantly must have quite an adverse effect on consumption....

Today I used cruise control at 80mph, on the A1 for 12 miles, and my consumption according to the OBD......never moved......

So what was happening the other day, I dont know.

Originally Posted by T-Cut

It's the average speed over the period since the last reset. Even a short stationary period pulls average speed down considerably and it takes a lot of continuous fast driving to bring it back to where you might expect. Generally, the average indicated will always be lower than you imagine. If you reset it while driving on a motorway say and then check the average after a 50 mile run, it will show what to expect more or (probably) less.

TC

Its the same as the mpg on the OBD.........its easy to lose it by some hard revving, and takes ages to get it back....

[T-Cut]

Originally Posted by bassman

Re your last point......Ive not got round to that yet, its been on my mind for a while, as although it always runs at 9 o'clock, it takes a good 5 miles to get there

Means very little other than it's running between 75C and 115C. Many diesels never get to 9 O'clock, ever.

I was looking to do the stat mod, but was actually going to ask you, before doing this, if the increased pressure in the thermostat opening late has ever (in your opinion) caused any radiator bursts or the like - - -

No that's not possible (IMO).

Ive studied the OBD mpg for a while now, and have seen 10mph, on pulling out of the petrol station up the bank in second gear, and the 300mpg on resetting the OBD at the top of a 4 mile downhill run....but Ive also noticed the difference in revs, between 3rd, 4th and 5th gears....I lost concentration yesterday while talking to passengers, and found I'd traveled a mile in 3rd gear(flat urban road) which normally I would have taken in 5th gear........the difference...about 600rpm..........now doing that constantly must have quite an adverse effect on consumption....

Fascinating stuff.

Today I used cruise control at 80mph, on the A1 for 12 miles, and my consumption according to the OBD......never moved......
So what was happening the other day, I dont know.

Me neither .

It's the same as the mpg on the OBD.........its easy to lose it by some hard revving, and takes ages to get it back....

As I've noted, averages are difficult to regain after a major excursion from norm.

TC

[bassman]

Originally Posted by T-Cut

Means very little other than it's running between 75C and 115C. Many diesels never get to 9 O'clock, ever.
TC

I'm a little apprehensive about trying this, Ive read lots you've written about this, and have it ready to print out to take to the car with me(easier than reading on the laptop), but not sure wether I've grasped the whole method yet.

Can I do any harm, or mess anything up, if I fail and have to pack in half way..

I'm not sure Ive got the co-ordination to carry the whole thing out....

Would I get the same results (and maybe more), by calling in on MarinaBrian and his magic wand and having a T4 done....

I could do with a look to see if my MAF is 100% anyway...

and If you think that the extra pressure wont affect the radiator or hoses, I'll go ahead with the stat mod, if necessary.....

[pm77]

Originally Posted by bassman

I'm a little apprehensive about trying this, Ive read lots you've written about this, and have it ready to print out to take to the car with me(easier than reading on the laptop), but not sure wether I've grasped the whole method yet.

Can I do any harm, or mess anything up, if I fail and have to pack in half way..

I'm not sure Ive got the co-ordination to carry the whole thing out....

Would I get the same results (and maybe more), by calling in on MarinaBrian and his magic wand and having a T4 done....

I could do with a look to see if my MAF is 100% anyway...

and If you think that the extra pressure wont affect the radiator or hoses, I'll go ahead with the stat mod, if necessary.....

If you mean reading the engine temp digitally, the worst would be resetting your trip counter.

[bassman]

Originally Posted by pm77

If you mean reading the engine temp digitally, the worst would be resetting your trip counter.

Would a T4 show the thermostat opening temperature.........