Rotax 912iS or 912ULS for Sling 2 ???

[3Dreaming]

Well, Tom, obviously you're not charging enough either!

I am charging what I think is fair.

[MrMorden]

In reality, fuel burn would be the least of my worries, especially if you’re burning auto fuel. Just me 2 cents.

I was not talking economy, but weight. An airplane that burns 3.6gph to go the same speed as one burning 4.5gph can carry less fuel to go the same distance. Having to carry less fuel weight offsets the heavier engine weight somewhat.

[drseti]

Having to carry less fuel weight offsets the heavier engine weight somewhat.

I look at it differently. Having lower fuel burn means you have even greater reserves, and more options when you carry the same amount of fuel.

[Warmi]

The kilobuck dongle is definitely a dealbreaker for me - and I'm a Rotax authorized heavy Maintenance repair center. With iS training. All my customers have ULS. If I ever get a customer with an iS, and he or she is willing to front the cost of the dongle, then maybe I'll consider working on one.

Just a few months ago I paid 6K for the 5 year rubber,annual and 200 hours inspection - given these prices being charged by mechanics a relatively minor 1K investment is pretty reasonable imho.

I think the person who did yours was the same person who told me you couldn't do a CT for less than $5,000. Having done several CT's I simply have to disagree with him. My normal charge is just a little more than half of that.

Well, my next annual and all further maintenance I will attempt to schedule with you - I am still looking for an avionics guy though , close to Chicago area.

[drseti]

FWIW, I flat-rate my labor for a condition inspection (100 hour, annual, or both combined) at $850. Customer pays for consumables (oil, filters, solvent, gaskets, spark plugs, etc.) at my actual cost. (Unfortunately, this does not include Rotax 5 year rubber replacement.) No sales tax on aircraft maint in PA. And, I only charge a little extra if you help.

[cam737]

Guys, you are supposed to be helping me decide on ULS or iS...not scaring me into neither!

But, lots of good inputs! Seems like no wrong choice. The Sling 2 has 39.6 gallons of fuel capacity. If the choices are so close, maybe the price differential will answer my question. $$$$

[TimTaylor]

If the iS with full fuel has enough useful load for my mission, then it becomes a question of engine cost. If the added cost of the iS is within my budget, that's what I would go for.

If the iS with full fuel is too heavy for the mission, and I have to go with less than full fuel, then I might as well get the ULS and go with full fuel. Range would probably be about the same, so why pay for the more expensive engine?

EDIT: If my missions are varied, and I can frequently take advantage of the iS and full fuel, I would go for the iS. There would be no disadvantage to flying with less than full fuel when the airplane is heavily loaded (versus ULS), except for engine cost.

[Warmi]

Well, this 5 year rubber replacement is unique to Rotax and can be expensive if you don’t shop around. In my case, I blew a tire at the airport that just happened to have a rotax heavy maintenance shop so I decided to leave my plane there do get everything done at once since it was already grounded and I had to wait for the new tire to arrive ...
Normally, my understanding is that a typical annual is about $800-1000 and if you are ELSA and have enough skills , you can do it yourself for free ...

Another major expense is repacking of the parachute , if you have one - I think for BRS is every 5 years and for GRS ( which I happened to have ) is every 9 years.

[Sling 2 Pilot]

Cam, I know Midwest is pushing the iS, did you share with Steve what we were told? Kind of curious why they wouldn’t have that info, as they are an authorized dealer. Unless of course they don’t agree, as they have had good results with the iS.

After flying both on my visit, I found the ULS better overall. It might have been that it did have fewer hours on it than the iS equipped Sling. For you, weight shouldn’t be an issue, so that’s one less thing you need to worry about. Additional cost and service history issues to date would be more of a concern. Also that dongel. If I were getting the iS, I’d want a dongel of my own in the plane just in case I got stranded.

Me, Id rather take the $1000 for the dongel and buy 300 plus gallons of 91-93 octane. . Or maybe buy the Mrs her own Bose A20. She’s still Wearing DC.

[cam737]

Hey Sling 2. No, Steve at Midwest Sky Sports is not pushing either engine. He thinks I will be perfectly happy with the ULS. I just want to avoid "buyers remorse" 5 years down the road and wish I went with the newer technology iS. My question for this post was triggered after talking to a gentleman at Rotax in Sebring who touted the many benefits of the iS. So, I'm wondering if anyone can talk me out of the ULS and into the iS...not yet.

It seems people are happy with both engines... Thanks for all the inputs gentlemen (women?). Lots of good points.

Cam

[cam737]

Hey J,

Yeah, great question. The Lockwood gentleman said auto gas sitting over 3-weeks is not an issue in the ULS because of the gas sitting in the carbs for an extended period. He specifically said it is not a problem in the iS. I'm not smart enough to know why?

Anyone, anyone?

Correction...The Lockwood gentleman said auto gas sitting in the carbs over 3-weeks is an issue in the ULS, not a problem in the iS.

Cam

[RV-12builder]

Had I gone with the certified RV-12 S-LSA, when it becomes available again, it will only be offered with the iS. I guess Van’s Knows something TAF doesn’t.

Are you sure the RV-12 SLSA will only be offered with the 912 iS engine? I’m building an RV-12 ELSA with the new iS fuselage, and Van’s has made it quite clear that the ELSA can be equipped with either a 912 iS or 912 ULS engine. In fact, the instructions that came with my fuselage kit have drawings for the fuel system for either engine. I’m surprised to hear the SLSA RV-12 won’t be offered with both engines, too.

Mark

[Sling 2 Pilot]

Had I gone with the certified RV-12 S-LSA, when it becomes available again, it will only be offered with the iS. I guess Van’s Knows something TAF doesn’t.

Are you sure the RV-12 SLSA will only be offered with the 912 iS engine? I’m building an RV-12 ELSA with the new iS fuselage, and Van’s has made it quite clear that the ELSA can be equipped with either a 912 iS or 912 ULS engine. In fact, the instructions that came with my fuselage kit have drawings for the fuel system for either engine. I’m surprised to hear the SLSA RV-12 won’t be offered with both engines, too.

Mark

When i visited the factory and Synergy last September, they had stopped the LSA production of the original -12. The last two Customer orders were changed to the iS. You can still order kits with the ULS or iS, but its my understanding the factory built -12 will be iS only.

They were supposed to have pricing for the factory built plane last October, but is been put off, still no word on when they will spool up production. The kits are a go. If i had put a deposit down end of last year I’d probably see a plane the end of the summer or fall. There were the two leftovers ahead of me, a production proof plane Synergy was to built and an east coast demo plane.

I want to fly yesterday...

[foresterpoole]

Does anyone feel that there is a better/faster throttle response in an IS vs ULS? I flew in an IS and maybe it was my imagination but it felt I got better and faster response. My sample size is pretty small, only one IS engine vs one ULS so it might not mean much....

[cam737]

The gentleman from Rotax said iS has better torque at higher power settings. I told him I flew a iS one day and a ULS the next day and I, albeit with "0" experience with Rotax engines, could not tell a difference. He said you probably could only notice the difference by using test equipment.
He said Lockwood put an iS and an ULS on an AirCam and they could definitely tell that there was less vibration on the iS vs. the ULS. He said real world, low and slow, touch and go, AirCam flying shows about a 15% fuel burn improvement...and about a 30% fuel burn improvement in cross-country-ECO mode.

FWIW...