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Did lt4 only come with manual bc it wouldnt avoid gas guzzler with the drag of auto?
ive always found it weird that lt4 only came with a manual. If an ‘auto’ was that important to you, them you got an lt1 in 96.
i heard gm didnt epa certify the lt4 with an auto and thats why it only came with a manual.
but i wanna propose a different theory.
Is it possible that with higher rolling resistance 275 fronts and 315 rear tires that the lt4 got combined with the drag of an automatic/torque converter, it wouldnt have met epa requirements and hurt gm’s CAFE (corporate average fuel economy) too much.
technology is difft now but back then it was common to see a manual car have like a 17/25 fuel economy rating and the auto version have like 16/25 fuel economy rating(though sometimes the auto’s highway was higher than manual due to a lower numerical rear axle ratio).
1 mpg in the city might not sound like much but in the corporate/ government qualification world it could mean quite a bit....
No. CAFE wasn' as big of a deal until Obama came in to try to fix the auto industry by removing cheap cars and getting automakers to increase prices with CAFE.
It boiled down to the cost of all the red tape. I'm surprised we got the lt4 period, there's no way they sold enough to pay for the extra testing and such.
St. Jude Donor '10-'11-'12-'13-'14-'15-'16-'17-'19-'20-'21-'22-'23
Originally Posted by dizwiz24
but i wanna propose a different theory.
Is it possible that with higher rolling resistance 275 fronts and 315 rear tires that the lt4 got combined with the drag of an automatic/torque converter, it wouldnt have met epa requirements and hurt gm’s CAFE (corporate average fuel economy) too much.
Remember, only the GS had those size tires.
The regular '96 6-speed manuals also got the LT4 engine with the same 255 front and 285 rear tires as the automatic cars.
GM does some strange things sometimes.
It wasn't until the C7 that the Z06 got an automatic option.
Even today, the 1LE versions of the Camaro are manual transmission only.
No. CAFE wasn' as big of a deal until Obama came in to try to fix the auto industry by removing cheap cars and getting automakers to increase prices with CAFE.
It boiled down to the cost of all the red tape. I'm surprised we got the lt4 period, there's no way they sold enough to pay for the extra testing and such.
The manual cars did get a better mileage rating than the automatics. However, I suspect that may not be the reason the LT4 got 6M and the LT1 got A4. I suspect it was simply marketing and perhaps production costs.
Below shows the original window sticker mpg and the revised mpg numbers for both the automatic and 6 speed.
For every engine and transmission combo the manufacturer has to go through testing. So if they offered LT1 and LT4 with auto and manual then they would have had to go through 4 iterations of the testing. By only offering each with one transmission they only had 2 iterations of the testing.
My guess is GM meant for the LT4 to be used in just GS's, but then found themselves with extra inventory, so decided to use the engine upgrade it in other vettes, but making it exclusive to manuals to help keep it somewhat exclusive.
Honestly over the years being on the forum, I don't think I've heard a good reason why the LT4 came with just the manual. Personally marketing foo if you asked me, last year of the C4 they should have just made all C4's an LT4 regardless if auto or manual.
Bummer many cars today you cant get with a manual. Some autos are real nice for overall driving but a paddle? sorry that doesnt take the place of rowing gears, fun factor is more important imo.
Last year of the c4. They did not care to much. C5 was going to be a game changer (and was)
Maybe a good contract on parts quantity / cost and had surplus from the GS? "hey lets make a regular car with this engine to use them up and people will like the extra 30hp"
Maybe a taste of more Power to get the people to say "oh the C5 will be incredible, I'' get one of those too"
I'm sure it was sales and business related as previously mentioned.
My experience in big business, is they had parts left and put them in something else and made the best of it, if not planned.
The 97 lt4 was limited to the slp ss and firehawks as an option. They may have better than the 96 because slp reworked and dynoed them. Since there was far less than the 3k built they were exempt.
I'm not sure Chevrolet could the LT4 to idle in gear in an acceptable fashion.
The 97 lt4 was limited to the slp ss and firehawks as an option. They may have better than the 96 because slp reworked and dynoed them. Since there was far less than the 3k built they were exempt.
I'm not sure getting Chevrolet could the LT4 to idle in gear in an acceptable fashion.
That actually makes the most sense. A "rough" daily driver in the 90's would have been a REAL tough sell.
Im not sure the automatic buyer would care. Even today buyers a funny about that extra pedal under the dash. The person looking for a M6 saw as a bonus a free grand sport engine on a base car. Some will claim since throttle body say Grand Sport it is one even if it's red, green, or purple.
St. Jude Donor '10-'11-'12-'13-'14-'15-'16-'17-'19-'20-'21-'22-'23
Originally Posted by dizwiz24
I didnt realuze only GS got the 315 rear and 275 front tires.
so you could have an ‘auto’ GS with lt1 and 315 rear / 275 front?
i suspect a lot of corvette buyers werent even told (but their dealer) about the manual 19 96 coming with a more powerful lt4 engine.
No, the GS was only available with the manual transmission.
The GS coupe had the 315 rear tires, but the GS convertibles did not.
All 1996 manual transmission Corvettes got the LT4 (bot only the GS coupe got the 315 rear tires)
All 1996 automatic transmission Corvettes got the LT1
Last edited by RollaMo-LT4; 05-16-2018 at 10:03 PM.
Pretty sure it was all down to cost. The more mix/match options you have makes the assembly line more complicated. On top of that, it was the last year of the C4 and they needed to tear everything down for the C5.
It's a combo of the cost to test/certify the LT4 with auto plus the issue of idle quality and idle emissions with an auto in gear. Remember, the LT4 had more cam overlap and would have therefore required a higher idle with the drag of the converter.
05-15-2018, 10:15 PM
Did lt4 only come with manual bc it wouldnt avoid gas guzzler with the drag of auto?
