This is nothing new, but it's finally got under my skin enough to write a post about it.

For years (like more than a decade) Jaguar in North America has been fiddling the numbers on horsepower, namely by calling the PS number HP, this is not such a big deal since it's just a few horses, i.e. 510PS being called 510HP...

But is the claimed power on the F-Type SVR that has me questioning the real numbers;

Here's what I mean;

F-Type V8S
JLRNA claimed 495HP, Euro marketing says 495PS
Strictly speaking, it should be 488HP, 495PS
But when you look in the actual tune file the header says 510PS
Stock F-Type V8S did 11.8 @ 119.5mph SOURCE

F-Type R
JLRNA claimed 550HP, Euro marketing says 550PS
Strictly speaking, it should be 542HP, 550PS
Stock F-Type R did 11.6 @ 122/123mph SOURCE

F-Type SVR
JLRNA claimed 575HP, Euro marketing says 575PS
Strictly speaking, it should be 567HP, 575PS
Stock F-Type SVR did 11.2 @ 126.3mph SOURCE

So...

The 55PS jump from V8S to R get's you 2/10ths and 2-3mph?
Or... the 40PS jump from V8S to R get's you 2/10ths and 2-3mph?

The 25PS jump from R to SVR get's you 4/10ths and 3-4mph?

Doesn't add up, and I don't see the RWD/AWD aspect coming into these numbers, since the V8S was run with drag radials, and the cars all have similar 60ft times...

What i'm basically trying to say is that IF the R numbers are correct, then the SVR is more like 600HP, not 575HP or 567HP...

Anyone agree or disagree with this observation?

 

Seen F-type R ads from dealers that say 542hp and not the general 550hp.

I guess it is seen as ok to fudge numbers a bit. Normally the opposite due to insurance etc.

An example is the Dodge Hellcat at 707hp which is actually more than that at the crank.

As for the SVR they probably ARE 25hp more, but not 575, more like 565hp or so.

 

But you don't pick up 3-4mph and 4/10ths at the drag strip with just 25hp when you're in the 11's, takes a lot more power than that...

 

Without running these cars on the same strip, on the same day, with the same driver in all 3 cars; this data is irrelevant.

 

Nope.

 

Several AWD R's like yours have run 11.6-11.7 @ ~122mph at different tracks around the world, seems pretty consistent numbers...

 

No argument there, but you don't have much data on the SVR yet, and so that point is in question. Also weight reduction and potentially less aggressive torque limiting at launch could be a factor.

 

1. I think you are right about the HP
2. I think any performance number that comes from a company is *usually* driven by marketing. That makes the numbers suspect.
3. The v8 - SVR difference looks right if it's 600. The wonkeyness starts when you put the R in between.
4. Even if the HP numbers and 1/4 times are 100% accurate, we're missing huge variables with torque and gear ratios. If the SVR torque curve is better and the gears tighter, you could gain a lot that HP numbers don't show.

 

Trans is the same across the board. ZF is well known for only selling one set of ratios for their 8 speed box.

 

We have several Rs and a few SVRs represented on this forum. It would be simple enough to resolve this issue by having one of each bolted to a load bearing dyno. When I dyno'd my stock V6S, it came in closer to 380 PS rather than HP.

 

I study drag times conducted by magazines religiously.

You are referring to ONE SINGLE drag time by Motor Trend during their Best Driver's Car Test.

No other test of the SVR has it trapping 126. In fact, most are around 122-123. I don't feel like pulling up sources.

No test other than the one you referenced has the SVR trapping above 123 and no test has the R trapping above 122. Granted, there are only a handful of SVR published test results.

It should be considered an aberration. Perhaps favorable test conditions or a press car with an overachieving motor.

The AMG GT-S, on the other hand, has considerably less power and every test shows a trap speed above 124 with more than one showing 127. If any car is being undersold, it's that one.

 

If you don't feel like providing sources then why should I feel like taking you seriously?

Actually it was Road & Track who provided that information, not Motortrend.

So where are the other tests you are referring to with slower times & traps? I can't find them...

 

Motor Trend got an 11.5@122.7 for the SVR. It's in their World's Greatest Drag Race 6 video.

For comparison, they got an 11.6@121.5 for the 2016 R.

2016 Jaguar F-Type R Coupe First Test Review - Motor Trend

Many testers have commented that both cars feel like they have 600 hp or more. I don't think there's any fudging of the numbers. If anything, the R&T test car might have had a "special" tune.

 

Also, I think what you are referring to is the difference in the measurement methods.
Germans use DIN, US use SAE numbers. Hence the discrepancy (575 SAE HP vs 567 DIN PS or bhp and so on).

 

I couldn't give a dog's hindside if you take me seriously. Buzz off.

 

The 8-speed transmission provides shorter gear ratios.

A C7 Z06 has considerably more power and less weight and doesn't get dissimilar drag results. It's all in the launch.

This C&D test of a RWD F type R did 11.8 @ 122. Another world's greatest drag race of a RWD coupe did 122.3, also 11.8

The results that are published and available seem sane and reasonable given the mild updates to the SVR.

 

Also, the original poster sourced results from different sources, which likely test differently with different conditions and different drivers. All of those factors, plus the fact that they likely take the best available result they can find and post it on their website rather than actually doing the testing themselves, mean they are not comparable. Motor Trend and C&D to me seem to be the most standardized and comparable testers.

 

I agree that the numbers don't strictly add up though it's hard to compare without a standardized test (more than one of each, same day, same track, same drivers). ....Maybe the SVR has more than a 25hp boost over the R....I think it's just as likely that the V8S is putting out more than 495...and perhaps more than 510.

Doesn't matter to me; Now I have the V8S, V8R and SVR software and can swap back and forth at will.

Dave

 

Hmm, this is a tough one. When I went 119.5mph the car was bone stock on DR's. In theory...an SVR making an additional 50hp AND weighing about 200lbs less...should get it to about 125mph.

Note: neither traps support Jaguar's factory HP claim...which seem low all around based on trap speeds.

 

Yep; just ran through the trap speeds and using the weights posted here on two different online calculators and I get;

- 119.5 mph trap speed = 506hp (crank)
- 122 - 123 mph = 538 - 552hp
- 126 mph = 593 - 597hp

....just based on that it would appear the V8S is underrated, the V8R is pretty much spot on and the SVR is underrated.

Dave