Un-scientific NX MPG experiment

[First_Lexus]

Over the c10,500 miles I've so far covered in my NX, I have an indicated mpg of 41.5 from the trip computer. The majority of my driving is on B-Roads and below, at speeds at or below 50 mph - any faster on most of the single track lanes around where I live is impossible. As an aside, a couple of weeks ago I had an interesting head-to-head on a blind corner with a tractor pulling a trailer full of grain. We both managed to stop. Just. If I'd have been going (say) 30mph rather than just over 20mph I'd guess we would have collided. A good reminder of the risks every so often is quite useful...

Anyway, yesterday I was visiting relatives about forty miles away. The trip involved a few miles of B-Roads and lanes at either end, and about 25 miles on the M4. As I wasn't in a hurry, I decided to see how high I could get the mpg on the trip (based on the in-car computer). This involved concentrating (hard!) on driving smoothly before the M4, and then setting the cruise control to 66mph on the M4 and staying in the left-hand lane for most of the journey. The motorway wasn't especially busy (Eastbound), and on the couple of occasions I came across slower moving vehicles I allowed the cruise to drop me to their speed - 55-60mph typically - for as long as I could bear it, waiting for a long empty stretch behind so I could pull out and overtake gently.

The result was an indicated 51.4 mpg, which I thought was pretty impressive. On the return journey, I set cruise to my usual 70mph and managed 41.5mpg. I was startled by the difference just a few mph can make. 

As I said in the title, this was entirely un-scientific. I guess the 'real' figures would be a couple of mpg lower than the computer indicated but even so, it entertained me for a couple of hours. Can anybody do better?

 

[i-s]

A few weeks ago I sold my Nissan Leaf. To hand the car over I had to drive it 160 miles from our home down to gloucester to hand it over. I planned my route and charge stops in order to minimise time spent, and needed to cover 76 miles to the first charge stop. Usual hypermiling techniques applied - very gentle, smooth, 55-60mph, etc. 

My husband was following behind me in our GS450h. When we arrived at the first charge stop after the 76 miles the trip computer on the GS was showing 52.8mpg. When we arrived at my mother's house (near gloucester, a bit over 150 miles from start) after a second charge stop,  it was still showing 50.9mpg over 178 miles (since it had been reset a few days and miles before starting this journey). 

[Ken R]

15 hours ago, First_Lexus said:

Over the c10,500 miles I've so far covered in my NX, I have an indicated mpg of 41.5 from the trip computer. The majority of my driving is on B-Roads and below, at speeds at or below 50 mph - any faster on most of the single track lanes around where I live is impossible. As an aside, a couple of weeks ago I had an interesting head-to-head on a blind corner with a tractor pulling a trailer full of grain. We both managed to stop. Just. If I'd have been going (say) 30mph rather than just over 20mph I'd guess we would have collided. A good reminder of the risks every so often is quite useful...

Anyway, yesterday I was visiting relatives about forty miles away. The trip involved a few miles of B-Roads and lanes at either end, and about 25 miles on the M4. As I wasn't in a hurry, I decided to see how high I could get the mpg on the trip (based on the in-car computer). This involved concentrating (hard!) on driving smoothly before the M4, and then setting the cruise control to 66mph on the M4 and staying in the left-hand lane for most of the journey. The motorway wasn't especially busy (Eastbound), and on the couple of occasions I came across slower moving vehicles I allowed the cruise to drop me to their speed - 55-60mph typically - for as long as I could bear it, waiting for a long empty stretch behind so I could pull out and overtake gently.

The result was an indicated 51.4 mpg, which I thought was pretty impressive. On the return journey, I set cruise to my usual 70mph and managed 41.5mpg. I was startled by the difference just a few mph can make. 

As I said in the title, this was entirely un-scientific. I guess the 'real' figures would be a couple of mpg lower than the computer indicated but even so, it entertained me for a couple of hours. Can anybody do better?

 

I find that the indicated mpg on the in-car computer tends to be optimistic and so have conducted brim to brim mpg checks from day one with my NX. Have now covered just over 14000 miles in close on 17 months of mixed driving (City/Motorway/A and B roads) and achieving an average 41.78mpg overall which I am quite pleased about. The best has been 46.32 and poorest 34.6 mpg. November through to March records the worst range due to the colder conditions.

[Grumps]

I have covered 9500 miles now in my NX. The in-car computer is a guide only, but I find that it is generally accurate to within 5%. There are various factors that can affect the recorded mpg you work out when filling brim to brim such as how much you top up after the fuel cuts out at the pump and how level the vehicle is at the chosen fuel pump.

The worst I have had is 36.5 (winter) and the best 48.7 (summer) but for the reasons stated above these may, or may not, be accurate. The best comparison is over a period of time and using the 'Fuelly' app I have recorded 42.2mpg over 9500 miles. This is 5.5mpg worse than the average of my previous car, a Audi Q3 TDI quattro, so overall I am very pleased with the figures I achieve from my NX.

[olliesgrandad]

On 8/27/2019 at 8:15 AM, i-s said:

A few weeks ago I sold my Nissan Leaf. To hand the car over I had to drive it 160 miles from our home down to gloucester to hand it over. I planned my route and charge stops in order to minimise time spent, and needed to cover 76 miles to the first charge stop. Usual hypermiling techniques applied - very gentle, smooth, 55-60mph, etc. 

My husband was following behind me in our GS450h. When we arrived at the first charge stop after the 76 miles the trip computer on the GS was showing 52.8mpg. When we arrived at my mother's house (near gloucester, a bit over 150 miles from start) after a second charge stop,  it was still showing 50.9mpg over 178 miles (since it had been reset a few days and miles before starting this journey). 

I do 170 miles in a working day so won't be wanting to buy a Leaf as I like to get home before nightfall 🏡