ro7939

Edmunds spec:
M/T 260hp/260tq
A/T 250hp/232tq

Per this site:
M/T 260/260
A/T 235/?

IIRC I saw one sight list A/T @ only 220hp.

Why did GM decrease power/tq in the A/T model? The only known reason is because the A/T is less rugged/durable vs. the M/T.

A/T SS model is in my future, no M/T considered. How costly is it to more closely approximate power/tq of the M/T model while maintaining same or almost same reliability in the A/T?

This subject is critical because A/T replacement cost is so high, especially as a ratio of vehicle value.

Tx!

Oldblue

Welcome to the site! I hope CJ sees this and jumps in! Other SS owners will advise you also!

Cokeybill

Whether you get the A/T or M/T, you really need to get the SS tuned. Without one the HP is a little on the low side of

LT4Man

Check out the threads that talk about the GM Turbo Upgrade. GMTU for short.

Loads of information regarding Automatic vs. Manual according to Chevrolet.

Welcome to the site and good luck in your search for an SS!

firemangeorge

Just a little FYI.
The lower HP/TQ numbers in the A/T(235 hp) only come into play for 1st gear.
(maybe 2nd gear too, not really sure on this)
It was GM's way of "taming" down the A/T SS models to make it a little more driver friendly on the low speed end of things.

prod

Yeah getting the gm turbo upgrade or a cheaper aftermarket tune will fix that issue. CJ can help you with that.

2005HHRauto

Huh..? It was done, just to reduce warranty claims, on the automatic…



The HPTuner chart below, is the amount of TORQUE that a stock HHR auto is programmed for, by gear.
So, in 1st & 2nd gear, torque is reduced to, anywhere from 63%-79%.
Just a simple "tune" to allow 100% of available torque, will make you smile…

XtremeSS

The short version, Yes. Gm does not believe the 4t45e can handle long term high power/tq.

Why don't you tel the OP what you have done to help the a/t stay alive with higher power levels. Of course this would include the OP to dive into hp tuners head first for shift time adjustments ect ect...

firemangeorge

[QUOTE=2005HHRauto;765869]Huh..? It was done, just to reduce warranty claims, on the automatic…

Yeah, that too.
Didn't want to throw the warranty issue out there and start another Internet debate on that again.

2005HHRauto

Here's a re-print from another thread:
350HP & 450' lbs of wonderful torque, provided by E47 Ethanol...

I've been beating up on my 4T45E for 6 years now.

Last time out at the track, 1.6s, 60' times, on slicks...
1.6s 60' times, are wicked abuse, on any trans...

Ive read that the 4T45E, holds up better, than the bigger 4T65E.
One shop owner states that he rebuilds, tons of 4T65E, & few 4T45E...

Mine shifts as good, as the day that I got it...

HPTuner settings have helped my 4T45E also, with my changes to
reducing shift times in half, from .250 seconds, to .125 seconds.
I've also keep torque reduction, at shift points below 3,000RPM.

I'm also running full synthetic Valvoline DEXRON VI ATF, because of the heat, created by all automatics.
Heat is the #1 killer of automatics, & only a full synthetic ATF, will save it, to live a long life...
As in full synthetic engine oil also, why would anyone not, want to run full synthetic, in everything you own.
This is the 21st century, after all.
I also put a pan on, that has a drain-plug, so that I can easily drain the ATF,
once a year, & the filter, every 2 years...

Also, don't run the 'sticky', super traction daliy street tires.
You don't want to 'dead-hook', all the time, on the street, spinning is fun,
& it will save your 4T45E from alot of stress...