[ANSWERED] Why does GM reuse engine names for different engines (eg. LT1)?
05-01-2019, 04:28 PM
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[ANSWERED] Why does GM reuse engine names for different engines (eg. LT1)?
The original question is here.
Jason's Note:
Hey gang -
We have to put "Ask Tadge" on hiatus for the next few months. The entire team is busier than usual. This includes the Chief Engineer. So that the team can focus on their "day job", we're going to cease sending Tadge questions for the next few months until after some ... event.... in July. I thought I heard somewhere that something special is happening in July. Anyone hear anything more substantial? ...
ArmchairArchitect asked:
Makes it very difficult when searching for parts. There are thousands of other possible combinations of 3 characters (or more) to use...why reuse the same engine names?
Makes it very difficult when searching for parts. There are thousands of other possible combinations of 3 characters (or more) to use...why reuse the same engine names?
Tadge answered:
For many decades, General Motors has used 3 character alphanumerics to denote regular production options (RPO's). Although it might seem like there are a virtually infinite number of combinations, they are not simply random letters and numbers. Starting in 1963, RPO's were organized to convey information about the type of option they represented. Not just on Corvette, but across the company, a convention was established that made the RPO's more logical. I can't tell you why, but engines fell under an "L" categorization, so for 1963, L75, L76 and L84 engines were offered. Transmissions fell under an "M" category and for '63 we offered the M20 and M35. Similarly, braking systems started with "J" and suspensions with "F".
Over decades, certain RPO's became brands of their own having special meaning to dealers and owners (Think L88 in '67 or the LT5 in the C4 ZR-1). There are times we will re-use an RPO when we feel like the brand equity conveys the mission of the modern hardware. It give people a reference of what they are getting when the check the option box. Todays ZR1, also featuring an LT5 is a good example. Sometimes it is not a specific RPO but groups of engines sharing a common origin that guide our choices. The LT and LS designations have been used on a quite a number of small block V8's and so are logical choices.
I appreciate that it might make it somewhat easier to track content if every engine had its own designation versus having to know engine RPO plus model year, but customers tell us they have more than just a passing interest in the engine in their cars. We see a lot of people investing in additional badging for their vehicles trumpeting their engine RPO. It is that passion we are trying to respect with our choice of engine option codes.
For many decades, General Motors has used 3 character alphanumerics to denote regular production options (RPO's). Although it might seem like there are a virtually infinite number of combinations, they are not simply random letters and numbers. Starting in 1963, RPO's were organized to convey information about the type of option they represented. Not just on Corvette, but across the company, a convention was established that made the RPO's more logical. I can't tell you why, but engines fell under an "L" categorization, so for 1963, L75, L76 and L84 engines were offered. Transmissions fell under an "M" category and for '63 we offered the M20 and M35. Similarly, braking systems started with "J" and suspensions with "F".
Over decades, certain RPO's became brands of their own having special meaning to dealers and owners (Think L88 in '67 or the LT5 in the C4 ZR-1). There are times we will re-use an RPO when we feel like the brand equity conveys the mission of the modern hardware. It give people a reference of what they are getting when the check the option box. Todays ZR1, also featuring an LT5 is a good example. Sometimes it is not a specific RPO but groups of engines sharing a common origin that guide our choices. The LT and LS designations have been used on a quite a number of small block V8's and so are logical choices.
I appreciate that it might make it somewhat easier to track content if every engine had its own designation versus having to know engine RPO plus model year, but customers tell us they have more than just a passing interest in the engine in their cars. We see a lot of people investing in additional badging for their vehicles trumpeting their engine RPO. It is that passion we are trying to respect with our choice of engine option codes.
Hey gang -
We have to put "Ask Tadge" on hiatus for the next few months. The entire team is busier than usual. This includes the Chief Engineer. So that the team can focus on their "day job", we're going to cease sending Tadge questions for the next few months until after some ... event.... in July. I thought I heard somewhere that something special is happening in July. Anyone hear anything more substantial? ...
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05-02-2019, 11:06 AM
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My birthday!? 
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05-02-2019, 11:33 AM
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Still wish they wouldnt do reuse names for a much longer period of time.
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05-03-2019, 09:15 PM
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I can understand the GM team being very busy for a while. Looking forward to the resumption of the "Ask Tadge" feature.
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05-06-2019, 07:50 PM
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I always had this same minor qualm about the engine designations. After Tadge explained it, it seems to make more sense to me. I think Z51 might be one of the best examples of an RPO package with brand equity across Corvette.
With that under wraps, I am guessing we may not see any more C7 "Ask Tadge" questions from here on out... No doubt we will be getting a lot of them about the C8 when he returns. The first time I've felt obsolete as a C7 owner
With that under wraps, I am guessing we may not see any more C7 "Ask Tadge" questions from here on out... No doubt we will be getting a lot of them about the C8 when he returns. The first time I've felt obsolete as a C7 owner
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05-09-2019, 10:52 PM
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05-12-2019, 09:48 PM
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The Z designation was for "Specialty" cars- Z/28, ZL1, Z-11, Z06,...........Now they just throw them around on vehicles like a pedophile in a school yard offering candy to little children. That's why today's GM's aren't worth anything anymore. They mass produce everything........Unlike Mopar and Ford. Check the numbers over the years.........And one more thing to clarify- the "M20,21,22" designation was carried over into the late '70's when GM was installing the BW ST-10. All those codes were for was to designate a close ratio or wide ratio tranny and not a Muncie which wasn't used after '74. People read the broadcast sheet and assume they have a Muncie in their car when in all actuality they have a ST-10. A Muncie has 7 side bolts and the BW has 9. Plus the BW was much stronger and more gears were available so lower rear end gears didn't have to be used. Just a little FWIW.........
Last edited by 68ACADIAN; 05-12-2019 at 09:58 PM.
05-15-2019, 12:51 PM
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The Z designation was for "Specialty" cars- Z/28, ZL1, Z-11, Z06,...........Now they just throw them around on vehicles like a pedophile in a school yard offering candy to little children. That's why today's GM's aren't worth anything anymore. They mass produce everything........Unlike Mopar and Ford. Check the numbers over the years.........And one more thing to clarify- the "M20,21,22" designation was carried over into the late '70's when GM was installing the BW ST-10. All those codes were for was to designate a close ratio or wide ratio tranny and not a Muncie which wasn't used after '74. People read the broadcast sheet and assume they have a Muncie in their car when in all actuality they have a ST-10. A Muncie has 7 side bolts and the BW has 9. Plus the BW was much stronger and more gears were available so lower rear end gears didn't have to be used. Just a little FWIW.........
Z-whatever has at least become a perfomance level designation, and not just a trim package.
06-27-2019, 01:59 PM
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Originally Posted by Tadge answered:
For many decades, General Motors has used 3 character alphanumerics to denote regular production options (RPO's). Although it might seem like there are a virtually infinite number of combinations, they are not simply random letters and numbers. Starting in 1963, RPO's were organized to convey information about the type of option they represented. Not just on Corvette, but across the company, a convention was established that made the RPO's more logical. I can't tell you why, but engines fell under an "L" categorization, so for 1963, L75, L76 and L84 engines were offered. Transmissions fell under an "M" category and for '63 we offered the M20 and M35. Similarly, braking systems started with "J" and suspensions with "F".
Over decades, certain RPO's became brands of their own having special meaning to dealers and owners (Think L88 in '67 or the LT5 in the C4 ZR-1). There are times we will re-use an RPO when we feel like the brand equity conveys the mission of the modern hardware. It give people a reference of what they are getting when the check the option box. Todays ZR1, also featuring an LT5 is a good example. Sometimes it is not a specific RPO but groups of engines sharing a common origin that guide our choices. The LT and LS designations have been used on a quite a number of small block V8's and so are logical choices.
I appreciate that it might make it somewhat easier to track content if every engine had its own designation versus having to know engine RPO plus model year, but customers tell us they have more than just a passing interest in the engine in their cars. We see a lot of people investing in additional badging for their vehicles trumpeting their engine RPO. It is that passion we are trying to respect with our choice of engine option codes.
Over decades, certain RPO's became brands of their own having special meaning to dealers and owners (Think L88 in '67 or the LT5 in the C4 ZR-1). There are times we will re-use an RPO when we feel like the brand equity conveys the mission of the modern hardware. It give people a reference of what they are getting when the check the option box. Todays ZR1, also featuring an LT5 is a good example. Sometimes it is not a specific RPO but groups of engines sharing a common origin that guide our choices. The LT and LS designations have been used on a quite a number of small block V8's and so are logical choices.
I appreciate that it might make it somewhat easier to track content if every engine had its own designation versus having to know engine RPO plus model year, but customers tell us they have more than just a passing interest in the engine in their cars. We see a lot of people investing in additional badging for their vehicles trumpeting their engine RPO. It is that passion we are trying to respect with our choice of engine option codes.
I get the legacy reasons why ("because that's how we've always done it"), but my question was more from a common sense standpoint. People would have the same pride and badging for their engines even if it was a unique engine code (and perhaps even more so). It sounds like you're at the mercy of some GM bureaucracy on this, so I appreciate your response regardless.
Last edited by ArmchairArchitect; 06-27-2019 at 02:01 PM.