NewHilux.net

The dyno numbers for my 2018 SR5 auto before and after tune are

Before
hp 92.3 (68.82 kW)
ft/lb torque 87.3 (118.36 Nm)

After
hp 136.4 (101.71 kW)
ft/lb torque 122.5 (166 Nm)

I don't know if theses are crank or rear wheel numbers but they don't appear to bear any relevance to Toyota's quoted numbers of 130 kW and 450 Nm?

If it's on a dyno it's rear wheel figures, unless they disassemble the powertrain and measure at the crank. Not sure you would want that though
Toyota's figures are at the crank on a test-bed. There's always going to be some substantial power loss through the gearbox and diff etc. And Toyota's figures are in ideal conditions on the test-bed with controlled air pressure and humidity etc.

47% power (and 74% torque) lost within the drivetrain seems very high though...

The below is from the Unichip website, it appears your before Dyno values are much lower, especially your before torque value....The increases from before to after are similar though.

Power 42% increase!
Standard: 96kw at the wheels.
Unichip: 136.9kw at the wheels.

Torque 41% increase
Standard: 390nm at the wheels
Unichip: 550nm at the wheels.

Every chassis dyno is different. Original SAE Gross figures tend to show the maximum potential of an engine, and they are conducted under laboratory controlled air, temp, humidity and fuel. There were no accessories on the engine other than exhaust manifolds. GM called this a GM20 test. Later came a GM1 test which was SAE net and this was conducted at higher air temp plus some engine accessories such as water pump. Then manufacturers had advertised power, for example Holden 308 engines in HT to HQ were advertised at 240hp whereas the actual SAE Gross was 227hp.
Later came DIN figures which far better simulated the operating environment of an engine and this will be what a Hilux is rated as. DIN is good for knowing what a car as presented might have but it is useless in understanding what an engine might be capable of. However chassis figures can vary wildly, especially torque as it is greatly affected by many factors like whether a converter is locked, what gear it is in and even tyre diameter. Plus dynos are calibrated differently. All you can bank on is the change on the same dyno. Plus peak torque means diddly squat. I’d much rather a torque curve that is basically flat from 500nM from 2000rpm until redline peaking around 600nM than some POS with a torque peak of 700nM with a cliff at 3500rpm and bugger all at 2000rpm.

I might add to a fine explanation from hk, if you have an auto gearbox the figures will generally be higher than a manual because of the torque converter multiplying effect. Lots of factors that change the outcome. And as hk said, the only reliable comparison is before and after on the same dino on the same day in the same gear. It's not reliable to give actual rwhp taken at different times.
Just switch the air conditioner on to see the difference in outcome.

Yeh but the figures should not vary that greatly between dynos. Dynos are like any other measuring device, and require regular calibration. They should only vary by +-2-3 units and thats it really, not 30kw and 270nm in this example.

Other factors will have a bigger impact, but I doubt many of these exist in this instance.

Figures do vary, including the operator and the air pressure etc etc etc. It's not that simple!
It's like hopping on the scales, your weight varies from minute to minute, depending on what you ate, when you had a pee etc etc etc despite the scales being accurate.
Dino measures are simply a snapshot at that time and those conditions.
And I might add that operators have a conflict of interest if they just sold you a tune or a chip!
The figures quoted by the op are reasonable if you compare before and after it's expected at around 30kw increase over before.

Thanks everyone

I know from first hand experience with bikes that run pressurised air intakes the difference it can make

Just a question - did have stock tyres on?

Falken Wildpeaks in standard size x 18