Achim,
actually I wonder. The 172 S according to Cessna cruises at 124 kts @ 75% with the O360 @ 8500 ft. 75% of 180 hp would be 135 hp at that altitude.
The 160 hp Cessna with the O320 was advertized at around 115 kts in similar conditions, so about 9 kts less with 20 hp less.
Now they claim 131 knots for the Centurion one. Ok, the Centurion 2.0s is a turbo engine, which means it can produce its full 155 hp up to about 8000 ft. That is quite a power advantage over the O360, let alone the O320.
That would be a good 20 hp more than the regular “S” has, albeit at full power. Not sure how these engines are run, but for advertizing purposes… 7 kts more off a turbo charged engine giving off 20 hp more?
One wonders. I hear from people who fly the 2S that it does have quite an edge over the 1.7 and even some over the regular 2.0
In terms of pure fuel cost, the results would be quite noticeable too.
The O360 uses between 35 and 40 lph, with todays prices here that is between € 74 and €86 per hour. (Actual prices Birrfeld LSZF)
The CD55 uses between 18 and 22 lph, with todays prices here that is between €32 and €41 per hour.
With the 172S’ 53 USG quantity and one hour reserve, that means it can fly 4.3 hrs @ 120 kts = 520 NM
The Diesel with the same fuel quantity and one hour reserve will fly 9 hours @ 125 kts = 1114 NM.
If I were to buy a new Cessna today, I think I knew which one I’d go for.
That is half the fuel price at even slightly higher speeds and a hugely increased range.
For me it would need the same short field performance. When I had a look at the 2.0 thielert the short field performance and the useful load was better on the std. AVGAS180hp.
When there is no AVGAS at all, then this is a moot point. I was at the 6. October airport HEOC in Egypt. This is where Egypt air trains all its pilot on a fleet of C172SP. They import 100LL specifically for this and it costs $5.60 per liter (not gallon!). Jet A-1 is almost free. In other places with similar training schools, there is no AVGAS.
Look at how many C172 Cessna sells these days. Another 50 to Middle East / Asian flying schools makes a big difference.
According to GAMA report, Cessna sold 106 C172 in 2013. 5.6% or a total of 6 were sold to Middle East and Africa combined.
That is half the fuel price at even slightly higher speeds and a hugely increased range.
I’ve seen it said several times (including in print) that Diesel is 50% of the cost of AVGAS.
But this overlooks the doubling of miles per litre. So here in the UK the fuel cost per mile is more like a saving of 75%. This may be different in other countries with different tax regimes.
(This has to be offset against higher purchase price and maintenance costs of Diesel engines)
Assuming AVGAS at 40 litres/hour x 2000 hours TBO at £2/litre = £80k
Diesel might cost around £20k
So difference in cost of engines and extra maintenance must be less than £60k to break even and I’d suggest £20k is probably pushing it, because that would be worth more than the airframe.
(Edited because I hit return too quickly)
We just flew EHLE-ENHF with some scenic deviations and back (approximately 3400NM) using 660 liters of Jet-A1 in 30.5 hours in a DA-40.
I guess we paid about 850,- euro in fuel costs or roughly 3 times less than we would’ve been able to do it in a LL100 aircraft like C172 and Jet-A1 was available at every single airfield we visited. It was rather funny to hear ‘PCA, please confirm you need jet fuel’ more or less every time we requested refueling.
