E-Type vs F-Type

[Heuer]

[JimmyS]

I often wonder what fuel consumption figures you would get by putting a contemporary engine in a 1960's car. The above picture graphically illustrates how vehicles have grown in stature and probably weight over the years.

[ChrisC]

:) looks huge in comparison doesnt it...

[ralphr1780]

And that's with an S2 with obviously 6" rims. You can imagine how an S1 would look next-by.

Earlier this year I enjoyed a very close look at the F, and can confirm that it is pretty tempting in many respects v/s other modern OTS models.
You cannot miss the several design details that are straightforward extrapolations from the E.
Haven't taken a test drive yet, but will surely do soon.

[Simon P]

You can almost see the process of osmosis going on as depreciation flows out of the one on the left and into the one on the right....

:D

[Dave K]

I had a good look around one before Christmas in a car park in Coventry. It was at an ice hockey match and the interior was stuffed full of hockey gear. I really like the like of the car.

I see a few of them when travelling up and down from Coventry on the A46 and saw 4 in Convoy on the Evesham bypass last Thursday with diguised front ends.

Dave

[Heuer]

It is very difficult to find photos of the two cars together with equal perspective. They always seem to put the F-Type to the foreground to avoid the size comparison. This is from that first shoot, presumably taken by a bystander:

And a couple of pro shots:



Clever use of perspective and placing leads the eye to assume the cars are probably of equal size.

[christopher storey]

About the only good thing I can say about the F is that it does in fact look better (rather less obese ) in the metal than on photographs , but the front is appalling with holes,vents, slashes making it look a total mess

[Dave K]

I can't wait to get mine....should be about 10 years time when the bottom has fallen out of the first ones produced. That is unless I win the lottery in the meantime.

Dave

[Woolfi]

"I often wonder what fuel consumption figures you would get by putting a contemporary engine in a 1960's car. The above picture graphically illustrates how vehicles have grown in stature and probably weight over the years."
The weight of a modern car is higher, but the cw ("wind draw") of an old car is muuuuch higher.
Therefore less gas consumption with the old car in the city, but more on long runs.
Regards Wolfgang Gatza

[JimmyS]

Good point about drag Wolfgang! Modern cars are usually aerodynamically 'cleaner' but their frontal area has increased and this offsets some of the benefit. Rolling resistance from comparatively fat tyres does them no favours too.

Regards,
Jim

[Heuer]

Indeed but the CD of an E-Type is 0.54 despite its low frontal profile! Modern cars are around 0.3 as they manage air flow better.

[ChrisC]

I'd more than happy having oodles of style and driving slower 8)

[stef]

Here are some pictures from Australian Jaguar Nationals at Easter - C-, D-, E-, and F-Type

[Durango2k]

Indeed but the CD of an E-Type is 0.54 despite its low frontal profile! Modern cars are around 0.3 as they manage air flow better.

Citroen SM, cW 0.34, Introduced in Geneva (!) in 1970.

2.7 ltr V6, VMax 230, usually overall 11 to 12 ltrs / 100 km.

Carsten

[PeterCrespin]

Indeed but the CD of an E-Type is 0.54 despite its low frontal profile! Modern cars are around 0.3 as they manage air flow better.

You could have a great Cd but still huge drag or, as with the E-type, a Cd which is only moderate today, yet still achieve low overall drag.

Drag is what costs speed and fuel and it is essentially the product of Cd times total frontal area. Reduce either and you get great results. Reduce both and you have a record breaker. Have high numbers for both and you have an SUV.

[christopher storey]

Personally, I regard the E type figures with a pinch of salt . For a start , it is never stated whether the figure is for the OTS, or OTS with hardtop, or FHC . Nor is anything said about differences in the different series, but I am quite sure that the open headlight cars would have differed from the closed cars . In any event , something which is not often said about the nominal coefficient is that it applies only with a precisely head on wind . A deviation of only a few degrees can make an enormous difference to the drag actually occurring . The most compelling thing however, which suggests that the overall drag of the E type is low is the steady speed fuel consumption figures . On the 3.8 tested by Motor, they were 25 mpg at 30 mph, and 21 mpg at 100 mph. Compare, e.g. an MGA twin cam for which the figures were 37 and 17.5 !

[Tony]

Now that does surprise me that that the different between 30 and 100 mph is only 4mpg in an E type. I can now think about driving a bit faster and not worry about the fuel being sucked away.

[PeterCrespin]

Personally, I regard the E type figures with a pinch of salt . For a start , it is never stated whether the figure is for the OTS, or OTS with hardtop, or FHC . Nor is anything said about differences in the different series, but I am quite sure that the open headlight cars would have differed from the closed cars . In any event , something which is not often said about the nominal coefficient is that it applies only with a precisely head on wind . A deviation of only a few degrees can make an enormous difference to the drag actually occurring . The most compelling thing however, which suggests that the overall drag of the E type is low is the steady speed fuel consumption figures . On the 3.8 tested by Motor, they were 25 mpg at 30 mph, and 21 mpg at 100 mph. Compare, e.g. an MGA twin cam for which the figures were 37 and 17.5 !

Very true, although the head-on figure is at least easy to standardise and benchmark across all manner of moving objects. Plus most, though by no means all, E-type owners (1) drive their cars and (2) do so with sufficient 'brio' that headwind generates the majority of the drag encountered. I daresay that the remaining sad cases who trailer their cars or never exceed fifty miles (or fifty miles per hour) on their drives, consume more by siphoning out stale stuff each Spring for use in their lawn mowers and daily drivers, than than via the carburretors!

I did read comparative numbers somewhere for the cases you cite Chris and from memory the 2+2 came out top on Cd though possibly not on drag. OTS top down was worst, as you'd expect, and top up was still not as good as FHC. What those numbers were based on (accuracy) and where I read them escape me. Personal experience definitely supports the deterioration in MPG at speed with the top down, especially my S3.

Pete

[Woolfi]

"Nor is anything said about differences in the different series, but I am quite sure that the open headlight cars would have differed from the closed cars . In any event , something which is not often said about the nominal coefficient is that it applies only with a precisely head on wind."
I know it "exactly":
the drag coefficient of a E-type series I Coupe is bad, the d.c. of a Sirs II 2+2 is worse and the d.c of a Series III Cabrio is worst.
You can calculate from the topspeed vs. power of a car , nearly to its total wind drag. The Serie III Coupe needs for 235 km/h 268 horsepower (DIN), the Series I Coupe only 210 hp (DIN). Therefore the total wind drag of the Serie III is 268 / 210 higher than the win drag of a Serie I Coupe.
This calculation is only "nearly" , because I din't care about the "rolling drag". But rolling drag is much smaller than wind drag.
The wind drag is rising with the speed in "quadrat".
The needed horsepower for a speed is rising in "cubic".
With these formulas you can calculate that the total drag of an e-type Coupe series I is less than 5% higher than the total drag of a modern Passat station waggon. Because the front area of the E-type is smaller the the front area of the Passat, the drag coefficient must be higher.
Regards Wolfgang Gatza