Best car for MPG at 80 mph

[300bhp/ton]

heebeegeetee said:

300bhp/ton said:

After Eight said:

Best car for MPG at 80 mph

Wow, that truly is the most critical aspect of buying any car

I guess it is for this particular vehicle.

No, it was called sarcasm.

[busta]

SonicHedgeHog said:

If you want to get better mpg then drive slower. By going slower you'll save money and arrive far less stressed.

Edited by SonicHedgeHog on Monday 13th September 16:01

As long as you remember to leave 5 mins earlier. Otherwise you'll arrive late and stressed.

[Turkey]

macdon2000 said:

Turkey said:

macdon2000 said:

I have an abused 04 plate mondeo estate.
At 56 miles an hour I can average 77mpg
At 80mph it drops to about 57mpg.
Compared to the 4litre V8 disco it replaced........(I now forget what petrol stations look like)

Are you going off the trip computer? I once drove a Mondeo TDCi that was about 10mpg optimistic on the computer (or more) on motorway work. Also, do you have a tuning box? This makes it even more inaccurate.

Sorry, but I don't believe your figures to be honest.

Edited by Turkey on Saturday 11th September 00:56

No tunning box but yes I am going off the trip computer. I have never worked it out manually but I generally get 650-750 miles to a tank (never drive with the fuel light on) so I don't think it's that far out. When I bought it the bloke I got it from had owned it from new and abused it (generally 5 up doing 90mph which is what he said (great sales pitch) IT WAS CHEAP!!) so I had low expectations (well after a V8 discovery you can't do worse). We have been amazed by the mpg. Done about 10,000 miles in the last 3 months and it has been great. Rattley at idle but great. Can't complain for £1800!!!

With the Mondeo, it should have a 58.5 litre tank, the best case for example is that you put 50 litres in to refill before the fuel light comes on, this gives from 59mpg to 68mpg. Impressive numbers.

So instead of the best case numbers above, if you are filling to the brim, you could be fitting more than 50 litres in. A guy on this forum got 61 litres into his Mondeo TDCI: http://www.honestjohn.co.uk/forum/post/index.htm?t... On previous cars I have put more fuel in than the tank capacity on occasion, the filler pipe must hold a couple of litres in many cars.

So working on the worst case, you only have 5 litres left when you refill, you could be putting 56 litres in from a usable 61 litres, which gives 53mpg for 650 miles, and 61mpg for 750 miles. Still impressive economy but more believable, especially if you cruise at around 60-70mph for a lot of the time.

My old ZR Diesel got 69mpg and 64mpg on two long journeys, this was with lots of time spent at 50-60mph. It did not have a 6th gear though, which could have given a few extra mpg. Driven normally though (70ish) it would do 43-50mpg on a run, where a taller top gear would have helped a fair bit.

What we really need to know is the amount of litres it takes to fill up your and the miles on that tsnk of fuel.

[anonymous-user]

SonicHedgeHog said:

At a constant 80mph you'll get about 45mpg from just about any 4 door saloon or hatchback.

I wish

[mig25_foxbat2003]

busta said:

SonicHedgeHog said:

If you want to get better mpg then drive slower. By going slower you'll save money and arrive far less stressed.

Edited by SonicHedgeHog on Monday 13th September 16:01

As long as you remember to leave 5 mins earlier. Otherwise you'll arrive late and stressed.

I rechristen this website: "Pistonheads - LEAVING EARLY MATTERS"

I get 31mpg average and I've only got a 318i to show for it. Same as my friend Tim used to get from his 535i Sport Auto, probably because I have to rev the nuts out of the M43 lump to get any kind of forward motion.

All this talk of Bluemotions is interesting - how much of their extra economy is down to those low rolling resistance tyres, and how horrendously do they affect cornering? Anyone got any stories to share?

[bigweb]

BMW 320 ED. Indicated 60+ mpg at 80 on the speedo. Crazily economical on the motorway!

[GingerWizard]

Ry_B said:

GingerWizard said:

My EP3 Type R Civic does 26mpg average. 38mpg on the M-way if kept around 80. Chin up, because this thread depresses me.

You aren't using VTEC enough, I get around 220 miles to a tank (full tank is around £55-£60)

having just looked at the last 2000miles i have done (in 4 weeks!!!) I have been averaging 24.2mpg. Intrestingly though did a heathrow run yesterday 237mile round trip (to MIL and FIL to airport with 2 cases, golf bag and MIL is a big ol' girl!) and my light popped on at 253 this afternoon.

[The fatboy]

about 30 litres a round trip from central manc to central brum doing house moving with a mate,
honda civic 1.6 (01)

M602->M6
around 80 before entering that st ATM zone and crawling with 1st and 2nd gear between J10-J8. then normal speed till leaving J6
full loaded.

M6->M602
vice versa but quicker.
empty loading.

Roughly total up 200 miles.

Edited by The fatboy on Monday 4th October 18:04

[bencollins]

CraigyMc said:

Fatman2 said:

Bonefish Blues said:

BarnatosGhost said:

Fatman2 said:

davepoth said:

Audi A2 1.2TDi. Drag Coefficient of .25, and the same engine that was in the 100mpg Lupo. Also an all aluminium body.

Sorry to piss on your fireworks but sadly drag coefficients don't do a lot for regular cars. Not sure why companies brag about this kinda thing when the determining factor is the arse end of the car

?

I wasn't the only one then

Yeah sorry, should have explained myself better

Drag coefficients are useful but unfortunately most manufacturers fail to design the back ends of 'regular' cars well enough to handle the flow of air once it's left the back end of the car. Spoilers are useful but given the shape of cars most, if not all, the benefits of a slick frontal shape is negated by a naff shaped rear i.e overly high and boxy.

So basically what you're saying is that you think the Cd factor listed doesn't include the back of the car?

How very very odd.

C

[HAB]

Delage D8-120 S.

Next question?

[Sam_68]

Fatman2 said:

Sorry to piss on your fireworks but sadly drag coefficients don't do a lot for regular cars. Not sure why companies brag about this kinda thing when the determining factor is the arse end of the car...

...Drag coefficients are useful but unfortunately most manufacturers fail to design the back ends of 'regular' cars well enough to handle the flow of air once it's left the back end of the car. Spoilers are useful but given the shape of cars most, if not all, the benefits of a slick frontal shape is negated by a naff shaped rear i.e overly high and boxy.

The drag coefficient does intrinsically measure the efficiency of the arse end, though. If you have an inefficient arse (a common problem from which I myself suffer...) then you will certainly get turbulence (another common problem from which I myself suffer...) that will increase drag, but the Cd figure will reflect this.

Drag coeffcients are literally only half the story, though: the important number is CdA - drag coefficient multiplied by frontal area.

It's easy to achieve a very low drag coeffient with something the length and bulk of a coach, but you still won't get much to the gallon out of it at 80mph.

OP: what you want is a Lotus Eleven Le Mans (the 'single seater' version with a rigid tonneau covering the passenger side), fitted with a 600cc modern diesel engine:




HTH

ETA: or perhaps one of these

Edited by Sam_68 on Monday 4th October 19:35

[vryes]

I would have thought an Octavia 1.6 TDi CR Greenline would have to be in with a shout.

My vRS averages about 52mpg at 80 and would have thought the Greenline would greatly improve on that.

Downside of the Greenline, people will keep trying to jump in the back at the traffic lights!! Even without the "Call CityCabs on 01******" sign on the back.

[daemon]

SonicHedgeHog said:

At a constant 80mph you'll get about 45mpg from just about any 4 door saloon or hatchback. We've all got stories of journeys where our trip computers showed awesome mpg, but the reality is that most of the time it's pretty average. And I'm saying that as someone who is obsessive about mpg. You may get a little more if you get a tiny diesel with a long top gear, but the extra gains will be marginal and it will be very wearing to drive long distances.

So, my advice is choose the car you like and get the diesel version. If you want to get better mpg then drive slower. By going slower you'll save money and arrive far less stressed.

Edited by SonicHedgeHog on Monday 13th September 16:01

got an easy 62-65mpg on every tank from my passat bluemotion with no sacrifices on size or driveability

[Steve_F]

On a trip from Perth (Scotland before the smart ar$es get there) to Wales we took a courtesy Fiesta my mate had instead of my 2.3 turbo Volvo.

Fiesta (we think 1.4 - definitely petrol) only managed to average a pathetic 33mpg (calculated) with a lot of motorway late night work and Welsh country lanes. I was seriously disappointed at this and was left thinking the Volvo wouldn't have been much worse.

So, not a 1.4/1.2/whatever petrol Fiesta. HTH

[y2blade]

Steve_F said:

On a trip from Perth (Scotland before the smart ar$es get there) to Wales we took a courtesy Fiesta my mate had instead of my 2.3 turbo Volvo.

Fiesta (we think 1.4 - definitely petrol) only managed to average a pathetic 33mpg (calculated) with a lot of motorway late night work and Welsh country lanes. I was seriously disappointed at this and was left thinking the Volvo wouldn't have been much worse.

So, not a 1.4/1.2/whatever petrol Fiesta. HTH

the volvo (yours is a T5 I guess) would have been much the same...but you'd have travelled in much nicer environment

I know what I'd rather do that sort of journey in

[carreauchompeur]

...Which is precisely why I run a 4.2 V8.

Hadn't used it for a while in favour of cycling to work (Really, really quick) or using the "weekend" MX5. However this morning I decided to treat myself.

Utter silent luxury. In fact I'd forgotten quite how silent. Wafting through the City Centre in an armchair. Meh, I know what I would rather spend my money on. Petrol versus horrendous depreciation on a boring eurobox. Mine'll do NEARLY 30mpg on a run

[CampDavid]

bigweb said:

BMW 320 ED. Indicated 60+ mpg at 80 on the speedo. Crazily economical on the motorway!

I was going to suggest this. The standard D is awesome enough and the ED is a big improvement on that