V90 D4 MPG Improvement

[anotherv60]

Originally Posted by Quacker

I believe that coasting in Eco mode is likely to actually use more fuel than when on the over-run with gears engaged in other modes. Not much but certainly not more economical.

Logically, when a modern petrol and Diesel engines are on the over-run, compression braking, no fuel whatsoever is injected. However when coasting, the engine must inject fuel to maintain idle speed, otherwise the engine would stop.

Thank you Quacker that is very interesting information, I hadn't made the connection with the engine and fuel injection when coasting!

You might be interested in what I heard today that "self driving tech" from uber consumes more fuel than driving the XC90 normally! That is how energy intensive those systems are! It made me wonder if there is a noticeable difference between driving normally and with Pilot assist - anyone noticed an improvement in mpg? I'm not in a position to carry out a proper study, perhaps others have noticed a difference, but interested in anyones thoughts on this!

[Quacker]

Originally Posted by anotherv60

Thank you Quacker that is very interesting information, I hadn't made the connection with the engine and fuel injection when coasting!

You might be interested in what I heard today that "self driving tech" from uber consumes more fuel than driving the XC90 normally! That is how energy intensive those systems are! It made me wonder if there is a noticeable difference between driving normally and with Pilot assist - anyone noticed an improvement in mpg? I'm not in a position to carry out a proper study, perhaps others have noticed a difference, but interested in anyones thoughts on this!

I've always assumed that relying on Adaptive Cruise or Pilot Assist, it matters not which, will easily be beaten on economy by myself. The reason being that a driver can anticipate way ahead and thus reduce the variation in speed, braking and accelerating quickly, that often goes with these two modes. Changing lanes in plenty of time to overtake, before the system detects cars ahead, mitigates the penalty somewhat, and so does manually driving and actually allowing the car to slow down naturally without braking, and accelerate gradually in traffic, allowing the gap between the car in front to vary more than the automated systems allow.

It is unlikely that the active systems take much actual energy to run. You can easily run a couple of HD cameras off a single USB 5V socket after all. Its the braking and accelerating that probably extracts an energy penalty.

I'd like to follow my car some day while someone drives it on a motorway in fair traffic with active cruise set to, say, 70mph, just to see how often the brake lights are activated, even on a downhill section. My feeling from driving the car for over a year, is that it brakes up to 200 times more often than I do [rough estimate] on a long motorway run in heavy but flowing traffic.

One of my sadder hobbies is, at times, to follow cars on Welsh A roads and count how often they brake compared to me. The most I've counted is 80 brake lightings for one of mine. Very often around 20:1 and I obviously keep up with them, although the gap varies a bit, but not ridiculously.

[Boatie]

Originally Posted by anotherv60

Thank you Quacker that is very interesting information, I hadn't made the connection with the engine and fuel injection when coasting!

You might be interested in what I heard today that "self driving tech" from uber consumes more fuel than driving the XC90 normally! That is how energy intensive those systems are! It made me wonder if there is a noticeable difference between driving normally and with Pilot assist - anyone noticed an improvement in mpg? I'm not in a position to carry out a proper study, perhaps others have noticed a difference, but interested in anyones thoughts on this!

Can't quote figures but I always get a lower MPG when using ACC. Stands to reason, ACC only reacts ie lifts off the throttle, when a possible cause comes within range of it's sensors. A Mk 1 Eyeball sees far further ahead and permits an earlier, less aggressive reaction.

[anotherv60]

Originally Posted by anotherv60

You might be interested in what I heard today that "self driving tech" from uber consumes more fuel than driving the XC90 normally!!

Sorry folks I missed some key words in this, it should read: You might be interested in what I heard today that "self driving tech" from uber consumes more than twice the fuel than driving the XC90 normally!

I was amazed at this claim, but have found some evidence to back it up from Ford et al: https://spectrum.ieee.org/cars-that-...f-driving-cars and here: https://www.nrel.gov/docs/fy17osti/67216.pdf

My friends Golf doesn't show the break lights when driving using the ACC which I think is really dangerous, but apparently that is common for the previous generation golf.

[anotherv60]

Originally Posted by Quacker

One of my sadder hobbies is, at times, to follow cars on Welsh A roads and count how often they brake compared to me. The most I've counted is 80 brake lightings for one of mine. Very often around 20:1 and I obviously keep up with them, although the gap varies a bit, but not ridiculously.

You say its a sad hobby, but imagine if everyone drove like you, we would probably save a small fortune in fuel, mind you the exchequer would be down in revenue!

[Quacker]

Originally Posted by anotherv60

You say its a sad hobby, but imagine if everyone drove like you, we would probably save a small fortune in fuel, mind you the exchequer would be down in revenue!

Yet I fail to get anything like the figures claimed by some others for the same model car. Probably because I do actually drive at a fair old pace, but rather less erratically than some. My car averages around 36mpg overall and about 39 on longer journeys. I have managed 42 but that is really rather tedious. Obviously to average 36, local short distance travel [less than 10 miles] comes down to around 30-32mpg.

[pdw1]

Hi,

I'm four months into a very enjoyable ownership of a V90 D4 Momentum. But the thing is my average mpg is in the mid-high 30s. I appreciate that I live in the countryside (i.e. slow, tractor-ridden windy roads), but I had hoped for a bit better, e.g. low 40s!!

Any suggestions as to what I might be doing wrong/might do better?

Thanks!

[WhatNext?]

I have disabled lane keeping assist and think the mileage has improved (although it was already pretty good with 33 mpg on my T5 XC60 compared to others)

[sammyblackbaron]

Originally Posted by pdw1

Hi,

I'm four months into a very enjoyable ownership of a V90 D4 Momentum. But the thing is my average mpg is in the mid-high 30s. I appreciate that I live in the countryside (i.e. slow, tractor-ridden windy roads), but I had hoped for a bit better, e.g. low 40s!!

Any suggestions as to what I might be doing wrong/might do better?

Thanks!

I'm 12 months in and averaging around 39mpg. Mostly higher speed dual carriageways - still nothing like the 60+ mpg that some other V90 owners on here enjoy.

[taylora]

Drove from Glasgow to Southampton last week mostly using Pilot Assist and managed 51MPG according to the computer and in reality was closer to 46MPG measured against a fill up.

The return journey was 56MPG computer and 52 measured. Pretty good considering we were doing between 75 and 80 most of the way.

My regular weekly driving I rarely see the MPG on the computer drop below 44 - that's 50% town and 50% dual carriageway/motorway. I'm really impressed with the economy on this car.

I have AC on all the time, use PA whenever it makes sense and have the tyres on ECO pressures at 38PSI.

Oh and I never use ECO mode.