Back in April 2013, I did a piece on some interesting engine name trademarks filed by GM that were likely for the Corvette and Camaro including the LT4, LT5, L88 and LTX. At that time, we had only met the new LT1 V8 that motivates the C7 Chevrolet Corvette Stingray fastback and convertible so beyond that first modern LT engine – we could only guess as to what GM might have planned for these engine names. Fortunately, information about new models like the 2015 Corvette Z06 have helped answer some questions while raising others.
The LT4 is the new Super-Vette Engine
Since then, we have learned that the 2015 Chevrolet Corvette Z06 will be powered by the new supercharged LT4 with 650 horsepower and 650lb-ft of torque so the mystery about that engine has been solved. At the same time, the formal introduction of the LT4 as the Z06’s supercharged heart raises questions about what the automaker might have planned for the other engine names. I had originally speculated that the LT4 would be a more powerful version of the new LT1, but like previous LT4 engines, it would be a mild performance engine. That obviously isn’t the case as the new LT4 is the most powerful GM production road engine of all time.
The LT5 was Once the Corvette ZR1 Engine
When GM trademarked the LT5 name early last year, I had guessed that the modern LT5 would power a C7 ZR1 after the previous LT5 powered the C4 ZR1. However, the introduction of the 2015 Corvette Z06 that is billed as the most track capable and most powerful Corvette of all time with the supercharged LT4 packing 650hp and 650lb-ft of torque has seemingly killed the ZR1. The new Z06 is so good that GM really doesn’t feel that they need a higher performance Corvette so in the meantime, it would seem like the LT5 will not power a C7 ZR1 – at least not right away.
Regardless of how awesome the 2015 Chevrolet Corvette Z06 may be, I do not believe that there wont be an even higher performance Corvette down the road. Considering that the C7 Corvette is now two model years old and the last few generations have lasted 8 and 9 years (C5, C6) so I would expect that the C7 Corvette will last for at least 7 years. Are we really to believe that the highest performance C7 will be introduced for the second model year of the generation and after that, nothing else will come along?
I don’t believe that for a second so I still think that GM could be keeping the LT5 and ZR1 names in their corporate pocket for a day when the need arises for something even hotter than the C7 Corvette Z06.
L88 and LTX are Still Question Marks
The final two engines from the early 2013 list of freshly trademarked GM engine names are the L88 and LTX.
L88 was essentially a race engine introduced in street form in the 1960s Corvette and back in 2013, I guessed that the L88 could be the Z06 version of the LT1. At that time, it seemed likely that the Z06 would still be a mid level performance package ranking between the Stingray and the C7 ZR1, but that is all out the window with the Z06 making the jump to the top of the lineup. Now that we know that the LT4 is such a monster, the L88 becomes a bit more of a question mark as it is hard to imagine an even nastier engine than the LT4 AND the LT5. The version of the LS3 engine that powers the current Chevrolet Camaro with the automatic transmission is the L99. This engine makes a bit less power than the LS3 that is mated to the manual transmission and there is a chance that at some point, the L88 could be something as simple as a lower performance derivative of one of the other LT V8s.
As for the LTX, I still expect that this will eventually be a high performance crate engine from GM Performance Parts – just like the popular LSX engine that GMPP offered for years to those folks building high powered cars with the convenience of a crate engine.
Of course, this is all speculation and in the event of things like the future Corvette ZR1, it could be years before we know more about the future of these engine names. However, with the next generation Chevrolet Camaro expected to arrive for the 2016 model year, perhaps the new Chevy muscle car will unlock more mysteries of these possible high performance GM engines.