Theodore writes:
So the other day I tested a Pontiac G8 GXP, just because I could. I ease away from a traffic light and as I go for the 1-2 shift, it gets hung up. Wouldn’t go into gear. I realize now that what I was experiencing was GM’s dreaded 1-4 skip-shift, except that of course I was trying to go into second, it wanted fourth, and, well, we just weren’t [synchro]meshing. Short of flooring it everywhere (not that I’d mind, just that you can’t always), what’s the best way to deal with – or outright eliminate – the skip-shift? And do any other cars besides GM’s family of V-8 six-speeds have this “feature?”
Sajeev answers:
Oh my damn! That’s my favorite bullshit modification to tilt CAFE standards for an automaker’s benefit. This scam is the most revolting proof that CAFE is a loophole-ridden system designed to make politicians feel good about their actions . . . and not much else. It might also help V8 GM products avoid the gas-guzzler tax, but I couldn’t possibly know for sure. [Ed: nope.]
Sorry, where was I? Right, the G8 GXP you drove that I could not drive.
Back in the day, the aftermarket made a bypass wiring harness that eliminated GM’s awful 1-4 skip shift. Dealer service departments rarely checked, or cared if they were installed. The same is true today, but the technology changed.
Thanks to OBD-II microprocessors (and the hackers that crack ‘em), today’s 1-4 skip shifters meet their maker with an ECU re-flash. It’s simple, effective and not too expensive. But that’s not all, folks: a quality ECU re-flash usually eliminates torque management in GM’s drive-by-wire throttle, increases horsepower for premium fuel by up to 25hp (more for turbocharged applications) and eliminates top-end speed limiters. It’s an epic win on all fronts.
[Send your technical queries to mehta@ttac.com]
My Challenger SRT with the 6 speed also has the 1-4 shift. An instruction sheet tells you the conditions where it rears its ugly head (i.e. precisely when you don’t want it). I’d appreciate any info on if I can easily remove it.
you can eliminate with a simple electrical modification. Jalopnik happened to have a little piece on it recently :
http://jalopnik.com/5252686/how-to-disable-gms-manual-skip-shift-for-seven-bucks
Yet another bone-headed decision by politicians and product managers.
A manual transmission is just that – manual.
I should be able to control the clutch and gear selection without any electro-nanny interference – period.
If the damn thing is going to tell me what gear to select, then I may as well buy a dual-clutch/manumatic/tip-tronic whatever box.
A late 60’s muscle car project is looking better each day. At least those cars let you do the driving.
-ted
Corvette owners have known this for years. Old news. It’s not uncommon for a new C6 to go straight from the dealer’s showroom to a “tuner”.
Don’t want a “tune”. Install a $10 jumper to the skip shift solenoid.
But without skip-shift, how will GM fans be able to trot out the “Corvette gets better mileage than a Camry” line?
Not that I don’t respect the Corvette or G8 or think that CAFE isn’t more full of holes than Swiss cheese, but GM tweaked both cars mightily to avoid CAFE, and real-world use (and by real-world I mean driving a Corvette like it was meant to be driven, not hypermiling it) doesn’t come close to EPA.
Making owners do a re-flash is silly. Put an ECO button on the control panel and be done with it.
I had a similar “GM is as dumb as a box of rocks” moment with a rental Impala. We were driving through the Virginia hills, using cruise control to avoid encounters with law enforcement. When I glanced down at the speedometer, it said 70, even though cruise was set for 60. I had my wife look this up in the owner’s manual. Right there in black and white were words to the effect of “the cruise control will not work on hilly roads.” Apparently, GM’s geniuses let the engine freewheel while in cruise control. Probably to squeeze a little more mileage out, but it renders the cruise control useless.
psarhjinian wrote: But without skip-shift, how will GM fans be able to trot out the “Corvette gets better mileage than a Camry” line?
On the highway, yes. A base Corvette will easily return close to 30 mpg at 70 mph, and my smaller 5.7L engined 2004 model will do 30 mpg at 80-85 mph….hardly hypermiling.
Now under WOT…it obviously requires a lot more fuel to make 430+ HP than it does to make 260ish, so the Camry “wins” there.
I suspect the Vette would use less fuel to accelerate from 0-60 in 7 seconds than the Camry would, though….
—–
by real-world I mean driving a Corvette like it was meant to be driven, not hypermiling it) doesn’t come close to EPA.
And how does this differ from any other car?
The selonoid overide is a great idea. I always figured if I had one of those, I’d just head for third gear rather than fourth.
I love my Prius, but I miss driving a stick…
This is exactly the kind of design flaw that I would refuse to take delivery of a car with. Fix it now, no cost, or no sale.
And how does this differ from any other car?
Because you drive a Camry at least moderately gently because, well, it’s Novocaine on wheels. If you’re not hitting (or at least approaching) EPA on it, something is wrong.
A Corvette was designed to be driven like a sportscar, so there’s not a whole lot of point about bragging about EPA highway mileage when the car has a very high top gear, or city mileage when it skips four gears on every shift. If you’re going to do that, you might as well start turning off the engine or down-drafting transports.
I suspect the Vette would use less fuel to accelerate from 0-60 in 7 seconds than the Camry would, though….
If you’re doing 0-60 in 7 or less in a Camry on a regular basis, you probably shouldn’t have bought a Camry. Personally, I can’t figure out the point of the V6 Camry at all, for the same reason I can’t figure out the point of a Corvette that skips three gears.
@ ex gm guy:
Our Virginia hills are deceptively steep in places, so I wouldn’t necessarily blame GM here. Any car will go faster than the set speed if a downgrade is steep enough.
Still, when I rented a Pontiac G6 a couple of years ago out west (not in the Rockies), it was clear that the car would not maintain its set speed (either uphill or downhill) as well as my Camry. One other thing about the G6: shifting the 4-speed auto from overdrive into third made no perceptible difference in engine braking.
so there’s not a whole lot of point about bragging about EPA highway mileage when the car has a very high top gear,
Why not? As I stated above, the car gets excellent mileage when cruising even at supralegal speeds. Thanks to the stout low end torque of the big V8 and low weight/drag design, it gets better mileage than any 911, BMW, Aston, Ferrari, etc. Plus, when you want to accelerate, you’ve got 5 other gears to choose from! Hell, a 7 liter Z06 delivers an easy 26 mpg at 80 mph. Is there a problem with driving the car at that speed?
Bottom line: these are real world sportscars that are driven in the daily grind. Sure, they are capable of near 200 mph speeds, but we all have to (grudgingly) recognize that we can spend precious little time at WOT in the real world. The easily defeatable skip shift function saves me from having to pay thousands in GG taxes…and for that I am grateful.
@psarhjinian
Personally, I can’t figure out the point of the V6 Camry at all, for the same reason I can’t figure out the point of a Corvette that skips three gears.
The point of the V6 Camry is that not everyone wants the thrashy 4 cyl in their transportation appliance, and you only give up a couple of mpg. The point of the skip shift feature is to game the CAFE number, and it skips two gears, not three.
@ psarhijinian–
The skip shift does NOT occur on “every shift,” as you say.
It occurs only under light throttle.
So the solution is this: drive the hell out of everywhere you go and avoid the skip shift
I would just like to say that that video only hints at the sound the G8 GXP makes under power. It is magnificent.
To psarhjinian. Kudos on suggesting an ECO button. I’ve been ranting and raving about how the auto manufactures should be doing that for awhile now. It’d be a great way to meet CAFE standards (selling vehicles with the default setting on ECO), and still give customers a chance to decide how much power and MPGs they want to have. Any suggestions on how to get this idea out to the automotive powers that be? I’ve toyed with the notion of sending letters, but we both know the auto industry’s (especially domestics) track record of listening to customers.
@reclusive_in_nature
Great idea about the default “ECO” setting. It would be nice for that to be standard on new vehicles.
On that note, I had test-driven an Insight recently and asked about the fairly low EPA numbers. The test drive clocked about 50 mpg, even with A/C blasting, with the “ECO” setting on. That appears to be close to what new owners are getting, though there’s not much data on it yet.
It made me wonder why Honda didn’t just use that as the default setting and make “Sport” (I know, an oxymoron with that vehicle) the optional setting. Wouldn’t that have raised the EPA rating?
Help me, I’m confused here. This skip-shift: I assume we’re talking about a slushbox with the manumatic thingy. right?
David Holzman,
No were talking about a real 6 speed manual with a real clutch.
I’ve had 3 Vettes with the 1-4 shifter and I’ve never had a problem, it almost never happens. Just don’t be a granny-shifter.
The Vettes high mileage comes from a super high 6th gear that basically cruises at idle-speed RPM.
I believe the latest Subaru STi model has an “ECO” setting. Check Liebermans review on this site. He preferred the most aggressive engine/suspension setting for normal driving though.
Off topic but of urgent interest: my brother just bought a new Prius, and wants to know if either of the following are worth getting (and in particular, does the sound shield really work, and does the teflon coating do anything):
UNDERCOATING/SOUND SHIELD………………….:.;………….$466.00
Rubberized, abrasion resistant coating applied to the
Undercarriage of the vehicle, prevents underbody rust and
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PAINT PROTECTION……………………………………………………….$489.00
Teflon coating buffed into the paint; prevents fading, loss
of gloss and oxidation. Protects paint from bird dropping, tree
sap and acid rain. No waxing! 8 YR WARRANITY
Thanks! David
Thanks Essen for the info on the 1-4 skip-shifter. Um, this is, uh, words failing me here. I am appalled that they would do something like this in a manual trans. How much extra production cost is there from this? Who thinks they know better when and where the car should shift than the driver? And do they get actual CAFE points for this???! I mean, next thing, the feds are going to be invading our bedrooms to monitor position so that we don’t do anything that would be politically incorrect! Who thinks up someting like this? They should lose their citizenship for being too micromanaging.
I knew about the low RPMs at high speeds on the Vette in 6th. Sounds like something the RX-8 should try.
I knew about the low RPMs at high speeds on the Vette in 6th. Sounds like something the RX-8 should try.
That would be dangerous, considering the Rx8 makes about as much torque at 1500 rpm as a hamster running in a wheel. Corvettes can actually accelerate quite well on level ground in 6th gear, since they make more torque at idle than a RX8 does at its peak.
As far as CAFE goes….the 1-4 skip shift is no biggie…and a small price to pay for not having a gas guzzler tax!
David Holzman: Yes, they get CAFE credit for this. That’s the infamous CAGS (Computer Aided Gear Selection)they came up with on the C5 Corvette to avoid the gas guzzler tax. It only works at low RPM; if you’re driving WOT you can shift normally. They claim it’s transparent to the driver but you never get used to it.
Here’s a $16 thingey that solves the problem. It doesn’t say anything about working on the G8, but it does specify it works on the ’10 Camaro so I have to assume it’ll work with the Aussie Poncho as well.
I put one of these on the 03 ‘Vette I had. Once it was installed I forget it ever had CAGS and enjoyed driving it like Zora intended.
that’s the infamous CAGS (Computer Aided Gear Selection)they came up with on the C5 Corvette to avoid the gas guzzler tax.
CAGS was already old news when the C5 debuted in 1997. It was introduced with the first 6-speed Corvette in 1989.
Never fails to amaze me, over the past 20 years, how so many journos and laypeople get their dander up from having to deal with CAGS…when a simple retune, or a $16 “thingy” eliminates the whole issue!
Of course, the “free” solution is to just wait another 1000 rpm to shift to second! Problem solved!
Do CAFE regulations or franchise agreements prevent GM dealerships from removing this feature themselves?
@doctorV8
CAGS is symbolic of some of the most annoying traits of the human species. This is when people don’t use their judgment–the existence of which is one of the reasons we have these absurdly big brains (absurdly big in the evolutionary sense).
Yes, doctorV8, in a way, you’re right. It is, fortunately a fairly simple problem to correct, but it’s just so stupid that it’s there in the first place. It violates the spirit of a manual transmission, and probably would save only a negligible amount of fuel, and furthermore, the surprise one might have at finding they couldn’t shift as they had planned could cause an accident.
This is like the old French bureaucracy where a non-french friend of a friend got to the end of several days worth of long lines, only to have her form rejected because she had used two different inks on the form. (Someone saved the day for this person, demanding to see the law that said you couldn’t use two colors of ink on the form. and then the bureaucrat tried to give the first woman a pen in a third color ink to sign the form.)
tedward,
Tampering with the vehicle’s electronics is a big no-no, no matter how innocuous. It would be analogous to removing catalytic converters or supplemental restraint systems.
doctorv8
That’s what I was supposing, as my old boss had a Corvette with skip shift, and the he was annoyed that the dealer wouldn’t remove it (and he bought it used so that was really puzzling to me).
I just don’t understand why that would be the case though, as the only party benefiting from the feature is GM itself. It annoys all their customers (from what I’ve read and heard) and it must annoy the dealers who have to deal with the subsequent whining, possible lost sales and loss of labor billables involved in the removal work. I’d always just assumed that there was some legal reason for the refusal, as nothing else makes sense.
I’ve been looking for a manual C4 Corvette for awhile now, and I swear what’s available out there is 99% automatic transmission. Which I absolutely will not drive in any sports car.
Reading about the skip-shift, I think I now know why all those C4’s are slushboxes.
…and I don’t think it’s a liability issue. Is someone going to wreck their now predictable Corvette and say, “but it did exactly what I wanted it to do!”
Assuming that there is a sane reason there must be a CAFE or EPA reg. that forces the company to try and keep their cars in an “as tested” state. But that leaves me wondering how the M5 stands with it’s 400 – 500hp switch, are it’s official numbers all generated off of the higher number? If not then I agree with psarhjinian and an eco button should be equipped in every ride. I’d absolutely adore a Corvette that had a 75hp eco mode, if only for the ironic thrill I’d get every time I disabled it/started the car and floored it.
I’m hoping to pick up a not-used-up GXP off lease in a couple years. That skip-shift jumper would get installed the day the car lands in my driveway, the ECU flash maybe sometime down the road.
I’m not sure why GM bothered to put this in the GXP – as mentioned, it doesn’t avoid the GG tax on this vehicle. I can only assume it’s a holdover from the Corvette where it does.
I would have really preferred this car in the wagon body. In less lucid moments, I consider grey-market importing one from Oz – and then dealing with being RHD.
The GG tax is not a flat fee, but rather a sliding scale. While CAGS and a 0.50:1 sixth have kept all Vettes (save the 2009 ZR1) from paying the tax altogether, I am sure the GXP’s GGT would be higher sans CAGS.
Thats the problem with GM cars, theres always something they manipulate or cost-cut wrong. My 98 Lumina didn’t have a low fuel light, for example. Its the only car I have ever driven without one, and I never understood why.
Uhhhh…yeaaaaaah (Bill Lumburgh)
simonisback—-since this ADDS cost its not cost cutting, and it really isn’t that big of a headache since it only occurs below 1500 rpm at 20% throttle.
Your 98 Lumina doesn’t have a low fuel light.Easy fix, find that thingy on the dash with the E and the F.If the pointy thing is at E you need gas.
doctorv8:
The GG tax is not a flat fee, but rather a sliding scale. While CAGS and a 0.50:1 sixth have kept all Vettes (save the 2009 ZR1) from paying the tax altogether, I am sure the GXP’s GGT would be higher sans CAGS.
Thanks for clarifying. In that light, it makes a bit more sense.
When/if I do acquire a GXP, I may have to incorporate that missing ‘ECO’ button somewhere along with the jumper – to override the skip-shift override, as it were.
CAGS was developed when the big 3 were keen on finding loopholes in the emissions/fuel consumption/noise regs rather than meeting them.
One other classic example was when they couldn’t get the Corvette to pass the driveby noise regs (measured on a sound level meter), so they got a Ferrari, which did pass, and drove it by the official and said to him – see that sounds much louder.
So they got a pass.
Then of course there was the Chrysler that switched to a different calibration for the engine when the hood was lifted, as it was during emissions testing.
It was fun working on stuff like that, technical solutions to legal problems, we don’t do so much of that these days, tho I’d have to say the space saver tire comes damn close to being a workaround (I’d admit that depending on where you are it may be an acceptable compromise, I haven’t had a puncture on my own cars for 20 years)
Thanks to OBD-II microprocessors (and the hackers that crack ‘em), today’s 1-4 skip shifters meet their maker with an ECU re-flash. It’s simple, effective and not too expensive. But that’s not all, folks: a quality ECU re-flash usually eliminates torque management in GM’s drive-by-wire throttle, increases horsepower for premium fuel by up to 25hp (more for turbocharged applications) and eliminates top-end speed limiters. It’s an epic win on all fronts.
except for one thing:
If the warranty shop catches you with altered ECU, you can kiss your engine warranty goodbye. Subaru, Audi, and others also void warranties for this.
Sounds like fun, with the exception of the sound of the turning signal.
It’s worth noting that the driver/owner of the GXP in this video is a moderator at the GRRRR8 forums. This is a first video-taped run of his GXP with the American Racing Headers Long-tube headers. So this is not stock.