Criticism of motorway performance

[raybarrow]

It's Christmas Eve, full of a cold (typical!) so a question.
Critics/Reviewers/etc often suggest a car is not great for on the motorway. Having had a variety of cars over the years I haven't found one that was 'bad' on the motorway. My cars have been generally 'middle of the road' types, e.g. Rover100, Austin Cambridge, Metros, Skoda, Astra, Ka (old and new), Fiesta.

Personally I would want it to be comfortable, able to cruise in the 65/70 range, fuel consumption not critical given that most of my driving is urban/suburban. Automatic with cruise control would be nice.

I get the feeling the the 'experts' want a motorway car that will power along at 80+, excellent maneuverability and high acceleration to make rapid, if uncomfortable for any passenger, progress on a busy motorway.

I accept that at 73 my view of motoring is 'an old codger's view' but I wonder what other people consider a 'good' type of motorway car, that in reality is useful for more likely the non-motorway journeys.

[redsturgeon]

I am probably in a very good position to answer your question.

Over the past six months I have covered about 25,000 miles up the M3, around the M25 and up the M11 with very little non motorway driving. Our car at the beginning of this epic was a newish BMW PHEV which was fine but had some shortcomings.

It is an auto that is fantastic around town where it will drive electric only and switch into petrol mode when more power or speed is required. During the first lockdown I went three months without putting any petrol in it using just the electric motor, it was smooth, silent and economical. On the motorway however it is quite an upright car (SUV shape) so there is wind noise and once it is on the motorway it runs on petrol only at about 40 mpg with a small tank giving between 300 and 350 miles range. Also if I was to put 50k miles on it in a year then depreciation would amount to many thousands.

After it became apparent that I would be doing mega miles I looked around and picked up a 16 year old diesel Honda Accord top of the range model with , sat nav, cruise control, air con leather heated seats and every gadget you can think of. Being a saloon, it was quiet and refined on the motorway at the legal limit and as a diesel it returns over60 mpg doing 2000rpm at that speed.

As a pure motorway car it is far better than the BMW ad cost me less than a tenth of the price we paid for the Beemer.

So in general for a good motorway car I want a saloon, with a long wheelbase, compliant suspension, comfortable seats, good heating and aircon system and a quiet cabin with little wind noise, cruise control, a low revving diesel with a long top gear and a manual box is also a bonus. Very different to the car I would want for hacking around B roads or sitting in town traffic. For the former something like a Mazda MX5 would be great but that would be an awful motorway car, while for town traffic I am very happy with my BMW PHEV.

John

[tjh290633]

I suspect that the answer is that you cannot get something for nothing. Hybrids at a constant speed have the same fuel consumption as a simple ICE of the same size and weight. It is only by regenerative braking that you can get any advantage. Plug-in Hybrids will have an advantage in short distance journeys but, as said above, on long motorway trips they are essentially the same as an ICE vehicle.

I used to do 30,000 miles a year, much of it by motorway. A diesel which did 75 indicated at 2,500 rpm was relaxing to drive and economical, but my current ICE, a 3-cylinder turbocharged 1.3litre, gives a better fuel consumption than my diesels. I now tend to run with the speed limiter set to give 70mph according to my satnav (Google Maps), and that seems to be beneficial for the fuel consumption, because of the steady throttle opening. It also removes the temptation to accelerate past other cars by getting up to 80, 85, or more for a shortish distance.

Looking at the complexity of screens for controlling everything, I think they are to be avoided. You cannot control the car and use a touch screen. Screens have their place but not for the uses to which they are put.

TJH

[9873210]

I suspect that the answer is that you cannot get something for nothing. Hybrids at a constant speed have the same fuel consumption as a simple ICE of the same size and weight.

This is not true.

With a simple ICE moving at a constant speed determines the operating point of the engine.* That will rarely be the point of maximum efficiency.

A hybrid moving at a constant speed can vary the operating point of the engine. Below some speed it will cycle between running the engine at maximum efficiency and off (which is also a point of maximum efficiency, if you work around 0/0). At higher speeds it will cycle between different operating conditions, all picked for best efficiency, rather than being forced by the car's speed.

Further the hybrid lets you use a smaller, more efficient engine than a comparable pure ICE car. A hybrid's engine need not deliver any torque at low speed (the motor provides torque at low speed) so you can spec an efficient engine that could not be used in a pure ICE car because it could not do a hill start on a moderate slope. Prii use Atkinson cycle engines and pure ICE cars do not.

* Or with a multi-speed gear box one of a few operating points, with one usually being clearly better. Even with a CVT the engines operating point must lie somewhere on a curve, which allows fewer choices than a hybrid, where the engines operations are only constrained by average power over many minutes. At any instant they can be anywhere in the engines operating envelope.

[jackdaww]

.

my need is for a car which is reliable, quiet , comfortable , economical and easy to drive .

able to cruise at 70mph , and able to tow a 1000kgs caravan .

my qashqai 1.2 turbo petrol automatic adequately meets all these requirements , forgetting the early battery issues .

some experts - eg top gear - grow old while overtaking .

yet this car has far more bhp than cars i happily towed with years ago .

nissan now do a mild hybrid , which probably does have efficiency advantages , but i very much doubt any significant real gain , due to the considerable extra weight of battery and motor , being carried at ALL times .

advantages of hybrids are the extra short term power boost available from the battery , and reduced pollution capability from full hybrids in built up urban areas .

ps. just how a manual box is a bonus is beyond me .

[dealtn]

... but I wonder what other people consider a 'good' type of motorway car, that in reality is useful for more likely the non-motorway journeys.

Comfort. I will be sitting in it for perhaps 6 hours of the day.
Range. 500 ish miles on a tank.
Toys. Decent Radio, SatNav, ability to use (hands free) phone easily - it will at times be a mobile office on that journey.
Decent boot. Quite possibly an SUV. The car will at times double up as the kit van for the team.
Seats. Mostly only one required, but at times 5 -7 (mostly not on the motorway).
Decent acceleration for the times when required (not particularly often).
Cruising. Comfortable at 80mph on the motorway.
MPG. Not particularly important.
Reliability. Good, and not particularly expensive, and parts freely available, on the (hopefully rare) occasions replacements are necessary (and can be serviced at my local, used for 20 years, garage - not at a marquee dealership).

[Dod101]

... but I wonder what other people consider a 'good' type of motorway car, that in reality is useful for more likely the non-motorway journeys.

Comfort. I will be sitting in it for perhaps 6 hours of the day.
Range. 500 ish miles on a tank.
Toys. Decent Radio, SatNav, ability to use (hands free) phone easily - it will at times be a mobile office on that journey.
Decent boot. Quite possibly an SUV. The car will at times double up as the kit van for the team.
Seats. Mostly only one required, but at times 5 -7 (mostly not on the motorway).
Decent acceleration for the times when required (not particularly often).
Cruising. Comfortable at 80mph on the motorway.
MPG. Not particularly important.
Reliability. Good, and not particularly expensive, and parts freely available, on the (hopefully rare) occasions replacements are necessary (and can be serviced at my local, used for 20 years, garage - not at a marquee dealership).

Ah so..........an admitted breaker of the law. Even if you choose to do that speed so much fuel pours through my engine at that speed that around 75 mph is about my maximum speed on a motorway, set my cruise control at about the same. I have a Q5 sport which suits me very well and would fit most of your requirements. Bought a few months old at £41,000. I do not call that particularly expensive.

Dod

[jackdaww]

... but I wonder what other people consider a 'good' type of motorway car, that in reality is useful for more likely the non-motorway journeys.

Comfort. I will be sitting in it for perhaps 6 hours of the day.
Range. 500 ish miles on a tank.
Toys. Decent Radio, SatNav, ability to use (hands free) phone easily - it will at times be a mobile office on that journey.
Decent boot. Quite possibly an SUV. The car will at times double up as the kit van for the team.
Seats. Mostly only one required, but at times 5 -7 (mostly not on the motorway).
Decent acceleration for the times when required (not particularly often).
Cruising. Comfortable at 80mph on the motorway.
MPG. Not particularly important.
Reliability. Good, and not particularly expensive, and parts freely available, on the (hopefully rare) occasions replacements are necessary (and can be serviced at my local, used for 20 years, garage - not at a marquee dealership).

Ah so..........an admitted breaker of the law. Even if you choose to do that speed so much fuel pours through my engine at that speed that around 75 mph is about my maximum speed on a motorway, set my cruise control at about the same. I have a Q5 sport which suits me very well and would fit most of your requirements. Bought a few months old at £41,000. I do not call that particularly expensive.

Dod

======================

.. but surely - the law doesnt apply to me ??

[gryffron]

A hybrid moving at a constant speed can vary the operating point of the engine. Below some speed it will cycle between running the engine at maximum efficiency and off (which is also a point of maximum efficiency, if you work around 0/0). At higher speeds it will cycle between different operating conditions, all picked for best efficiency, rather than being forced by the car's speed.

Your point is valid, BUT...
* Modern ICEs have very good efficiency/load/rev bands anyway.
* Electric transmission is less efficient than mechanical. Yes, some early hybrids still have mechanical transmission too. But such would still be subject to your "varying revs" argument, you can't have it both ways.
* A hybrid car is typically much heavier. This doesn't only matter uphill. It increases rolling resistance on the flat too.

Current tests IGNORING THE STARTING CHARGE show diesels are still more fuel efficient on motorways than hybrids. The longer your journey, the less relevant the initial battery charge. Petrol ICE vs hybrid is a closer competition, but diesels still clear winners for emissions on a long motorway run at the moment.

And hybrids are much more expensive to buy, and less reliable due to having more components to go wrong.

Gryff

[dealtn]

Comfort. I will be sitting in it for perhaps 6 hours of the day.
Range. 500 ish miles on a tank.
Toys. Decent Radio, SatNav, ability to use (hands free) phone easily - it will at times be a mobile office on that journey.
Decent boot. Quite possibly an SUV. The car will at times double up as the kit van for the team.
Seats. Mostly only one required, but at times 5 -7 (mostly not on the motorway).
Decent acceleration for the times when required (not particularly often).
Cruising. Comfortable at 80mph on the motorway.
MPG. Not particularly important.
Reliability. Good, and not particularly expensive, and parts freely available, on the (hopefully rare) occasions replacements are necessary (and can be serviced at my local, used for 20 years, garage - not at a marquee dealership).

Ah so..........an admitted breaker of the law. Even if you choose to do that speed so much fuel pours through my engine at that speed that around 75 mph is about my maximum speed on a motorway, set my cruise control at about the same. I have a Q5 sport which suits me very well and would fit most of your requirements. Bought a few months old at £41,000. I do not call that particularly expensive.

Dod

======================

.. but surely - the law doesnt apply to me ??

I spend most of my time on the motorway between 70 - 80 mph, which appears to be the same as the majority. Happy to admit it and not be a hypocrite denying it. The law applies as equally to me as anyone.

[tjh290633]

I suspect that the answer is that you cannot get something for nothing. Hybrids at a constant speed have the same fuel consumption as a simple ICE of the same size and weight.

This is not true.

With a simple ICE moving at a constant speed determines the operating point of the engine.* That will rarely be the point of maximum efficiency.

A hybrid moving at a constant speed can vary the operating point of the engine. Below some speed it will cycle between running the engine at maximum efficiency and off (which is also a point of maximum efficiency, if you work around 0/0). At higher speeds it will cycle between different operating conditions, all picked for best efficiency, rather than being forced by the car's speed.

Further the hybrid lets you use a smaller, more efficient engine than a comparable pure ICE car. A hybrid's engine need not deliver any torque at low speed (the motor provides torque at low speed) so you can spec an efficient engine that could not be used in a pure ICE car because it could not do a hill start on a moderate slope. Prii use Atkinson cycle engines and pure ICE cars do not.

* Or with a multi-speed gear box one of a few operating points, with one usually being clearly better. Even with a CVT the engines operating point must lie somewhere on a curve, which allows fewer choices than a hybrid, where the engines operations are only constrained by average power over many minutes. At any instant they can be anywhere in the engines operating envelope.

You cannot beat the laws of physics. Both cars require the same amount of energy to move at a constant speed. The only source of energy which a hybrid has is the fuel input to the engine. You cannot create energy by having a battery. You can use braking energy to charge up the battery, or when descending hills, but that energy has only come from accelerating or climbing the hill.

A plug-in hybrid has an advantage for short journeys, but on a longer journey, once the battery has lost its charge, it is no different from any other vehicle.

TJH

[9873210]

I suspect that the answer is that you cannot get something for nothing. Hybrids at a constant speed have the same fuel consumption as a simple ICE of the same size and weight.

This is not true.

With a simple ICE moving at a constant speed determines the operating point of the engine.* That will rarely be the point of maximum efficiency.

A hybrid moving at a constant speed can vary the operating point of the engine. Below some speed it will cycle between running the engine at maximum efficiency and off (which is also a point of maximum efficiency, if you work around 0/0). At higher speeds it will cycle between different operating conditions, all picked for best efficiency, rather than being forced by the car's speed.

Further the hybrid lets you use a smaller, more efficient engine than a comparable pure ICE car. A hybrid's engine need not deliver any torque at low speed (the motor provides torque at low speed) so you can spec an efficient engine that could not be used in a pure ICE car because it could not do a hill start on a moderate slope. Prii use Atkinson cycle engines and pure ICE cars do not.

* Or with a multi-speed gear box one of a few operating points, with one usually being clearly better. Even with a CVT the engines operating point must lie somewhere on a curve, which allows fewer choices than a hybrid, where the engines operations are only constrained by average power over many minutes. At any instant they can be anywhere in the engines operating envelope.

You cannot beat the laws of physics. Both cars require the same amount of energy to move at a constant speed. The only source of energy which a hybrid has is the fuel input to the engine. You cannot create energy by having a battery. You can use braking energy to charge up the battery, or when descending hills, but that energy has only come from accelerating or climbing the hill.

TJH

You are wrong here. You do not understand the laws of physics. Your argument has all the sophistication of saying that you cannot improve the fuel efficiency of car by using a multispeed gearbox.

[Dod101]

Ah so..........an admitted breaker of the law. Even if you choose to do that speed so much fuel pours through my engine at that speed that around 75 mph is about my maximum speed on a motorway, set my cruise control at about the same. I have a Q5 sport which suits me very well and would fit most of your requirements. Bought a few months old at £41,000. I do not call that particularly expensive.

Dod

======================

.. but surely - the law doesnt apply to me ??

I spend most of my time on the motorway between 70 - 80 mph, which appears to be the same as the majority. Happy to admit it and not be a hypocrite denying it. The law applies as equally to me as anyone.

Ah, that is different. The original version gave the impression that you habitually cruise at 80 mph. No matter, not my business and I was only observing, not accusing. I must admit that much of my long distance driving does not tend to be on motorways and much of it is average speed controlled anyway.

Dod

[quelquod]

For me cost comes a distant second to a comfortable, quiet and smooth ride. Enough performance to easily keep up with any traffic and to briskly overtake when required, with freedom from any tendency to wander or tramline, and enough range to comfortably cover a full day’s driving, say Fife to Cornwall, without refuelling or worrying about needing to. There are enough driving hassles and risks to contend with without any inconvenience added by the car. Admittedly I cover less than 10000 motorway miles in a year and like the OP I qualify as an old codger. The earlier arguments about the efficiency of a hybrid don’t sway me - like for like they don’t approach the efficiency of a diesel on a long run which barring substantial change will be my preference for some time yet.

[Dod101]

For me cost comes a distant second to a comfortable, quiet and smooth ride. Enough performance to easily keep up with any traffic and to briskly overtake when required, with freedom from any tendency to wander or tramline, and enough range to comfortably cover a full day’s driving, say Fife to Cornwall, without refuelling or worrying about needing to. There are enough driving hassles and risks to contend with without any inconvenience added by the car. Admittedly I cover less than 10000 motorway miles in a year and like the OP I qualify as an old codger. The earlier arguments about the efficiency of a hybrid don’t sway me - like for like they don’t approach the efficiency of a diesel on a long run which barring substantial change will be my preference for some time yet.

I was about to agree with you but you mentioned diesel. I have had a diesel car and hated it! Petrol for me which I suspect will 'see me out'.

Dod

[DrFfybes]

I have a Q5 sport which suits me very well and would fit most of your requirements. Bought a few months old at £41,000. I do not call that particularly expensive.

Dod

You have a different definition of "expensive" to me

Actually, thinking about it, if I work out all the cars I've ever owned and knock off the sale price of the 2 I didn't drive until they dropped, I reckon that's about my total lifetime spend on cars. Of course your's still has some residual value, but that is a chunk of cash for something to get you from A to B.

Now if you include motorbikes in that calculation, then it goes a bit wrong, but they're for fun as well as transport.

Paul

[airbus330]

2L plus diesel (by preference) or petrol, quiet, low revving with plenty of torque. In its comfort zone between 70-90, good ventilation. But, if you are doing a lot of miles, which I used to do, very comfortable seats were the deciding factor. I journeyed in plenty of brands as I often used hire cars and BMW were the brand for me as driver. The only car I used which came a close 2nd. was a Skoda Superb, which crops up as a great value choice on some car review sites. As a back seat passenger trying to sleep, the S series Mercs were great.

[Dod101]

I have a Q5 sport which suits me very well and would fit most of your requirements. Bought a few months old at £41,000. I do not call that particularly expensive.

Dod

You have a different definition of "expensive" to me

Actually, thinking about it, if I work out all the cars I've ever owned and knock off the sale price of the 2 I didn't drive until they dropped, I reckon that's about my total lifetime spend on cars. Of course your's still has some residual value, but that is a chunk of cash for something to get you from A to B.

Now if you include motorbikes in that calculation, then it goes a bit wrong, but they're for fun as well as transport.

Paul

Being of a certain age and being on my own, I just buy a car that I like. 4WD and very responsive gives me a feeling of comfort and security. You are being supremely sensible I will give you that because I must have spent quite a lot of money on cars over the years. Such is life.

Dod

[quelquod]

2L plus diesel (by preference) or petrol, quiet, low revving with plenty of torque…
BMW were the brand for me as driver.

Mine too - as an old codger it has to be a 5 series 6 cylinder, none of the more recent odd-shaped monstrosities which lurch about our local filling stations. I prefer the tourer for its golf-club-swallowing capacity, a large enough engine to deter most traffic-light fiends and 4wd to ease poor weather driving. Still the best compromise between a limo and a driver’s car and with a nod to the OP superb on motorways.

I was about to agree with you but you mentioned diesel! I have had a diesel car and hated it!

IMHO a bit of an outdated generalisation . Mine is as quiet inside as the equivalent petrol model which it leaves for dead on economy and performance on any journey, and the old bugbear of slow cabin heating a thing of the past with its supplementary electric one for short cold-weather journeys. Sadly the name’s now likely forever unfairly tarnished by reference to its smoky forebears.

[Mike4]

I was about to agree with you but you mentioned diesel! I have had a diesel car and hated it!

IMHO a bit of an outdated generalisation . Mine is as quiet inside as the equivalent petrol model which it leaves for dead on economy and performance on any journey, and the old bugbear of slow cabin heating a thing of the past with its supplementary electric one for short cold-weather journeys. Sadly the name’s now likely forever unfairly tarnished by reference to its smoky forebears.

Yes I too wondered if Dod had perhaps had a pre-common rail diesel as yes, they are horrid.

A common rail diesel is a completely different animal and for performance and driver experience, is indistinguishable from a petrol engine. From outside the car, the engine still sounds rather diesel-like though quieter and that's about it.

And getting back to the original topic, my Mercedes van is the most comfortable motorway vehicle I've ever driven. So quiet it's hard to tell the difference between 30mph and 80, blistering performance that catches out many a sports car and the most comfortable driving seat I've ever had. The only downside is, oddly, fuel consumption is appalling.


(Edit to fiddle with html - still not quite right!)