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Post by rosieuk on Nov 10, 2018 13:45:22 GMT
At the moment I'm driving both a Wolseley 18/85 II and a Kia Rio 1.4i 16v. One is a 4 spd manual and the other 5 spd. Horsepower is 85/95 and the gearbox ratios & final drives are almost identical. So I thought I'd do an experiment..
I filled the tank on the Kia and drove a whole tank using 1-4 only (technically 2-4 mostly because 1st is so low it's useless bar the Swiss alps).
The Wolseley does 260 miles approx before it needs a refuel and wouldn't you know it the Kia did 264 before it wanted filling up. Wolseley should do 26mpg urban and the Kia did 31mpg. Which means the difference is about 19% (there is a weight difference on paper).
This difference can be accounted for by the aerodynamics effectively. So moving from the aerodynamic equivalent of a small country house to a modern(ish) design nets you almost a 20% saving in fuel.
As the best MPG the Kia has managed normally is about 37 - aero & 5th gear combined nets a 40% improvement over the Wolseley.
This isn't entirely scientific but I do find it interesting and also quite worrying because I'm fairly sure from previous vehicles I've owned with sump heaters that if I fitted DFD with a coolant heater I'd be perfectly capable of equalling the 31mpg figure for the 4spd Kia on average which means a 5spd Wolseley using the coolant heater would be fairly close (within 5%) to an EFI car built in 2010 (assuming a similar 5th ratio, which is actually lower than I'm happy with).
What price progress?
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Post by Penguin45 on Nov 10, 2018 18:07:50 GMT
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Post by snoopy11 on Nov 11, 2018 8:55:53 GMT
The mileage returns quoted are fairly interesting
I am certain that my fuel injected Crab is better on fuel even taking into account the modifications than it was as a standard 1800
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Post by rosieuk on Nov 11, 2018 18:27:27 GMT
The mileage returns quoted are fairly interesting I am certain that my fuel injected Crab is better on fuel even taking into account the modifications than it was as a standard 1800 It should be - it'll be more efficient on warm up, which will be the major gain - another gain will be in town because of better fuel metering. I'm not so sure about motorway but I expect you could fit a scan gauge to your car and get by the millisecond readings. If the figures from the old 2.2 safrane with the sump heater are applicable to the Wolseley then on the single carb engine you could expect 33.2mpg urban mixed and 43mpg on a fast run (the safrane pre heated made a 27% gain on shortish journeys) - which if you consider the weight of the car and the rather dismal aero is pretty good going. Especially since my 86hp Accent is 44 combined. Combined mpg with 50/50 urban/motorway would be around 38.2! Better than the Kia has ever managed and not far off the Accent with a much more sensible engine (12v lower torque-max rpm) I'd be very interested to know what the FI ADO17 gets? The aerodynamics of the Wolseley aren't fantastic. Problem areas are the window seals - the glasshouse - the huge gaping gap underneath (which is why a chin spoiler will give you an mpg gain) - the wheel arches could both be spatted f & r and the grille surround area could benefit from a chamfer - but that would be *major* body work. A work around for the glasshouse would be spoilers to the climbing trim forward the front doors (the shiny gutter piece) with the intent of widening the air flow around the window surrounds. I'm not sure because I've not measured it but the windscreen angle might be a little too upright. I've thought about using those wheel brush things you see on buses as a conformable front valance spoiler and sill side spoilers - that will adjust with speed. Wheel spoilers (directly in front of the wheels as a body extension) will also help to control air flow. As in the picture, what you want is attached airflow - the bonnet -> roof -> boot isn't bad (bar the windscreen rubber) and the panel sides are OK but it's the underbelly and arches that need looking at - with the glasshouse sides. Sorry about the essay but I thought the results looked interesting. It's also important to note that the coolant heater (the finned sump isn't really suitable for a sump heater) will not only provide better fuel consumption but it'll also protect the engine from cold starts. Even when the weather is warm a pre heater is worth using. There was a air filter heater and intake heater available for cold weather crabs but I've never been able to find one - and they'd be a nightmare to get re manufactured. - although since they'd fit on any HS6 car... |
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Post by rosieuk on Nov 11, 2018 21:14:42 GMT
Had another think about the aero and I could never figure out why the mini/1800 and I assume 11/1300 continued the drip rail down along the front A pillar to where it meets the front wing.
Now it makes some more sense.
Not only does it funnel water from the screen up and over the A pillar - which is a very good idea when you've been doused with washer fluid as many times as I have (thanks Hyundai); it also acts to channel air up and over, boundary layer the roof airflow, as well as I suspect (and the smooth chrome? will help this) acts as a spoiler for the airflow going back to the rear. That's why the rear extractor windows work so well - I will bet that airflow reattaches just before the front edge of the extractor - and this helps pull air through the car.
The picture of the rear end of the Maxi suggests it because the extractor grilles on the rear C pillar are right along the same line along the glasshouse.
The question therefore is: was this a deliberate feature or just something accidental? I don't know but I'd love to see a computer simulation of the airflow across the glasshouse and roof as standard and with the gutters "shaved". I'd expect to see that the standard model has cleaner airflow along the sides and I'd also expect a slight improvement in lateral cross stability because the upright of the gutters along the roof might well create a boundary layer helping to channel airflow back and resisting flow interruption from both sides.
If I remember and this I back when I was 5 or 6 the Cortina we had had similar gutters and wasn't bad in crosswinds but the Sierra (which was effectively the same car, different body) was lethal in any motorway crosswind and didn't. I wouldn't be at all surprised if lateral flow across the roof was disrupting fore > aft flow and creating lift across the roof surface at an angle to the direction of travel at varying rates (due to wind speed). It would *certainly* explain the phenomenon of the early Sierra getting unsettled passing under motorway bridges - what with the disturbed air flow..
And I'm going to stop now because my brain is hurting..
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Post by rosieuk on Nov 11, 2018 21:25:11 GMT
Just had another look at the picture Penguin posted... If you look at the flow over the roof it looks like the flow has gone up the line of the gutter - remained attached at whatever the effective airspeed is but will be high enough to have an effect on the flow across the chord & span of the roof helping to keep that attached and stopping disruptive lateral flows.
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