I always thought that all of the 5th Gen Camaro SS were equipped with an LS3 Engine from the C6 Grand Sport, but then I started to hear about a De-Cammed version of the LS3 called an L99. Does anybody know the differences

The last time GM ever called an Engine an L99 was when they made an optional "Baby LT1" for 94-96 Chevrolet Caprice Sedans

(I know that this is NOT a Camaro Forum, but I am discussing a Corvette Engine.)

 

The 2010-2015 Camaro SS comes factory equipped with either a LS3 Manual or an L99 Automatic – both are similar designs, but they have some differences. The main difference between the two is the LS3 produces 422HP and the L99 produces 400HP.

Layout
•The L99 and LS3 engines are both built on the same platform, featuring 6.2L of displacement and eight cylinders. The camshaft of the L99 engine has slightly less duration than the one found in the LS3, giving the Camaro SS paired with this motor a smoother ride. The compression ratio of the L99 motor is 10.4:1, as the pistons have valve reliefs machined in the top halves of the pieces. The LS3’s compression ratio is 10.7:1.

Performance
•Consumers might favor the slight power increase in the LS3 over the L99, even though both engines demonstrate high performance values. The LS3 engine is rated and advertised with 422 brake horsepower and 408 lbs/ft of torque. The L99 engine has a slightly less horsepower output rating, as the vehicle is advertised with 400 brake horsepower and 410 lbs/ft of torque.

Transmission
•The basic difference between the L99 and LS3 motors is that each one was built for a specific type of transmission. The more powerful LS3 engine is paired with 2010 Camaro SS models that feature the manual transmission. Likewise, the L99 comes from the factory in automatic Camaro SS automobiles from the same year.

Fuel Efficiency
•Fuel consumption has become an important aspect to modern consumers when buying vehicles. Automobile companies had to completely redesign engines in order to maximize energy yet maintain performance values. Because both the L99 and LS3 engines share the same layout and many of the same parts, the fuel efficiency does not differ greatly between the two. However, the LS3 engine is advertised with an average of 16 miles per gallon in the city and 24 miles per gallon on the highway. The L99 is rated at 16 miles per gallon in the city and 25 miles per gallon on the highway.



Some Additional Differences w/ LS3 Engine
•L99 camshaft is different — having a little less duration and a little less lift, both of which give the engine a smoother idle.
•L99 has a cam phaser and, to get the additional piston-to-valve clearance required when cam phasing changes, the pistons are different parts having valve reliefs machined into their tops. The reliefs lower the compression ratio to 10.4:1.
•L99 PCV system is different having its oil separators in the valve covers rather than down in the valley like the LS3.


http://lmgtfy.com/?q=DIFFERENCE+BETWEEN+LS3+AND+L99

 

I thought the major difference was that the L99 had a cylinder deactivation feature to help fuel efficiency numbers.

 

 

The manual GS have a dry sump and I don't think the Camaro has that except the Z28 LS7.

 

I thought about a 6th gen camaro before I bought my latest vette.

I recall another issue with the L99 involving the use of low octane gasoline triggering something computer based in the engine which substantially lowered performance until corrected.

 

Ok, I come from the Camaro world and actually own both a L99 adn LS3 equipped SS Camaro at the moment.
LS3 is in the manual trans Tremec TR6060 cars, 426 HP
L99 is in the auto trans cars, 400 HP
Main difference is cylinder deactivation in the L99, cam, heads, comression are different from LS3
L99 is no slouch and actually when modded to remove the DoD but retain the cam phaser they can really scream. In stock form the cars run very similar times since the auto trans shifting itself makes up for the HP difference.
I can also tell you the LS3 is much more "fun" to drive especially when coupled with NPP that became available in 2013 in the Camaro.

 

I have a 2015 SS Camaro and a 2013 Corvette Grand Sport Convertible (Wet sump LS3). The dry sump was only installed in the manual GS Coupes. The L99 in my Camaro runs just fine and the DOD (Displacement On Demand) doesn't really do much for gas mileage. The DOD can be tuned out or you can install a device in the OBD II port that disables it until you unplug it. The L99 has plenty of power.