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The Car Thread ... !
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It's cool, but Cadillac styling already looks dated. I saw this car on Friday. The rear design is a complete trainwreck.
I'd rather just get a S550 or E63.
bunnspecial
macrumors G3
It's not surprising that you haven't heard of them-there were only 450,000 MGBs sold in the US. It was only the most popular sports car(in terms of production numbers) until unseated by the Miata. It's also so obscure that when Mazda sat down to design the Miata, they said "we want to make a modern MGB" and actually designed the exhaust system on the original model to sound as close as possible to an MGB.
The 6 cylinder MGC(which was heavily based on the MGB, and in fact IS an MGB from the firewall on back) was a de facto replacement for the Austin Healey 3000. It was never sold as an Austin Healey because the Healey family looked at it and said no 🙂 (the MGC was not very successful with a production of 9,000 over 2 model years-a lot was due to some serious handling problems that originated from the 700lb lump of cast iron driving it). The engine in the C does share some parts with the engine in the Healey 3000, but also shares some parts with the BMC B series engine since it's basically one of those with two extra cylinders stuck on the front. The MG Midget and Mk II-Mk IV Austin Healey Sprite were the same car.
Out of curiosity, do you know what purpose higher octane gas serves/what it does?
Speaking of oil ...
😀
Got it changed yesterday, thought it was funny timing in the context of the last couple of days of oil discussion. I use my local dealer, they have a huge service center (a whole dedicated building for maintenance type work), they're quick, professional, it's actually very reasonably priced, and all my service records are in the same place.
Anyway, used the factory spec'ed 5W20 Motorcraft (specifically, 5W20-QFS full synth). Also reminded me I need to check my catch can!
😀
Got it changed yesterday, thought it was funny timing in the context of the last couple of days of oil discussion. I use my local dealer, they have a huge service center (a whole dedicated building for maintenance type work), they're quick, professional, it's actually very reasonably priced, and all my service records are in the same place.
Anyway, used the factory spec'ed 5W20 Motorcraft (specifically, 5W20-QFS full synth). Also reminded me I need to check my catch can!
I don’t Care much for the extended headlights running in a downward position. If they would have deleted that strip and integrated LED’s somehow into the lower half of the front bumper, that would have been much more aesthetically pleasing.
Feel free to elaborate further, short answer based off my knowledge; It helps Prevents Engine knock at a higher compression and aids in thermal efficiency with the engine from running to hot. Also, Higher octane fuels traditionally have higher levels of cleansing additives (I don’t know that all High octane fuels do), Which assists in allowing the engine to run cleaner throughout its lifespan.
I gather you’re asking likely based on what you know to share or educate your knowledge on fuel, for reference, the point behind my post and reply to that the forum member was referring to those using 87 octane in a performance vehicle requiring 91, being the owner likely doesn’t know or care what fuel they use because its a ‘cheaper’ solution, specifically ignoring the manufacturers recommendation.
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bunnspecial
macrumors G3
Higher octane fuels have one purpose and one purpose only, and that is to reduce "knocking"-also called detonation, pinging, or pinking. Essentially what it is-in a back of the envelope sort of way-where the fuel effectively instantaneously burns instead of in a smooth, controlled flame that propogates from the spark plug.
Higher octane fuels are less susceptible to this occurring, and knocking is also more likely to occur with higher compression ratios and with more load on the engine.
For maximum efficiency and performance, it is ideal for peak cylinder pressure to be achieved when the piston reaches top dead center after the compression stroke. Because the flame takes time to propogate, it's necessary to fire the spark plug while the piston is still rising in the compression stroke. This is usually specified in degrees of crankshaft rotation "before top dead center"(BTDC). This is called the ignition timing. At higher engine rotational speeds, it is necessary to fire the spark plug sooner(the rate of flame propogation is somewhat independent of the linear speed of the piston). As engine speed rises, the ignition timing is "advanced" and at lower speeds it is "retarded." Advancing and retarding are also done in response to engine load. In a non-computerized car, this is all handled by the distributor-centrifugal weights cause the ignition to advance as the distributor spins faster, and and engine vacuum is used to determine load and advance the timing. In a computerized car, a timing map is built into the ECM and relies on signals both from the crank position sensor and the manifold absolute pressure sensor.
In any case, having the timing too advanced-regardless of the octane rating of the gas and the engine compression-can result in pinging. Similarly, retarding the timing too much for the conditions results in a loss in both power and efficiency as the fuel will still be burning as cylinder pressure drops during the power stroke.
In all cases, it is desirable both for power and emissions reasons to advance the spark as much as the engine will support without pinging.
With a distributor based ignition system, you generally can only make changes in the start and end point of the advance curve. Changing the specifics of the curve-including the the total amount of advance and also the profile of how it advances-can only be accomplished by physically changing the weights and springs that control this. In the MG world, we send our distributors off to a guy(at this point, really just one guy) who optimizes the advance curve for what we tell him about our engine and then-again-just set the timing within the parameters of what he's built into the distributor. On the advice of many folks who know these cars inside and out, I run mine at 32º BTDC maximum mechanical advance(no vacuum). That puts the idle advance at around 16º BTDC. I'll add that this is set by physically rotating the distributor in the engine block, and I measure it using a xenon strobe that flashes every time the #1 spark plug fires while looking at a mark on the front harmonic balancer that indicates TDC.
Computerized cars, however, include an additional element in that they have a knock sensor, which is really just a microphone. When the knock sensor detects knocking, the engine retards the timing until it goes away.
The point of all of this is that with a computerized car, you really can't HURT the engine by running a lower than specified octane rating. The primary consequence is that you will see a loss in power, and possibly a slight loss in fuel efficiency. It won't "crud up" your engine or otherwise damage it-remember that the ECM is still going to run as much advance as it can.
If your car calls for 91+, use it by all means, but you're not going to see catastrophic damage from running lower than that.
Higher octane fuels are less susceptible to this occurring, and knocking is also more likely to occur with higher compression ratios and with more load on the engine.
For maximum efficiency and performance, it is ideal for peak cylinder pressure to be achieved when the piston reaches top dead center after the compression stroke. Because the flame takes time to propogate, it's necessary to fire the spark plug while the piston is still rising in the compression stroke. This is usually specified in degrees of crankshaft rotation "before top dead center"(BTDC). This is called the ignition timing. At higher engine rotational speeds, it is necessary to fire the spark plug sooner(the rate of flame propogation is somewhat independent of the linear speed of the piston). As engine speed rises, the ignition timing is "advanced" and at lower speeds it is "retarded." Advancing and retarding are also done in response to engine load. In a non-computerized car, this is all handled by the distributor-centrifugal weights cause the ignition to advance as the distributor spins faster, and and engine vacuum is used to determine load and advance the timing. In a computerized car, a timing map is built into the ECM and relies on signals both from the crank position sensor and the manifold absolute pressure sensor.
In any case, having the timing too advanced-regardless of the octane rating of the gas and the engine compression-can result in pinging. Similarly, retarding the timing too much for the conditions results in a loss in both power and efficiency as the fuel will still be burning as cylinder pressure drops during the power stroke.
In all cases, it is desirable both for power and emissions reasons to advance the spark as much as the engine will support without pinging.
With a distributor based ignition system, you generally can only make changes in the start and end point of the advance curve. Changing the specifics of the curve-including the the total amount of advance and also the profile of how it advances-can only be accomplished by physically changing the weights and springs that control this. In the MG world, we send our distributors off to a guy(at this point, really just one guy) who optimizes the advance curve for what we tell him about our engine and then-again-just set the timing within the parameters of what he's built into the distributor. On the advice of many folks who know these cars inside and out, I run mine at 32º BTDC maximum mechanical advance(no vacuum). That puts the idle advance at around 16º BTDC. I'll add that this is set by physically rotating the distributor in the engine block, and I measure it using a xenon strobe that flashes every time the #1 spark plug fires while looking at a mark on the front harmonic balancer that indicates TDC.
Computerized cars, however, include an additional element in that they have a knock sensor, which is really just a microphone. When the knock sensor detects knocking, the engine retards the timing until it goes away.
The point of all of this is that with a computerized car, you really can't HURT the engine by running a lower than specified octane rating. The primary consequence is that you will see a loss in power, and possibly a slight loss in fuel efficiency. It won't "crud up" your engine or otherwise damage it-remember that the ECM is still going to run as much advance as it can.
If your car calls for 91+, use it by all means, but you're not going to see catastrophic damage from running lower than that.
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Personally I don’t mind the tail lights/rear of the vehicle, even though they are shaped like the number seven. My biggest complaint is the wheels. The wheel package looks like it’s just not fitting for this specific car, it doesn’t emphasize sporty at all to me given its the “V” Series. But then again, Cadillac is about lots of chrome accents and the wheels look something off a dated Chrysler. The Quad tipped exhaust was a nice touch.
This view makes it look more menacing. Seeing the headlights from this angle isn’t as off putting as compared to a side angle from the previous photo. I think GM did a nice job inside and out.
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Bunnspecial covered it pretty well. The only thing I would add is for vehicles that don't call for 91+ octane fuel, you are pretty much wasting money putting higher octane fuel in them. The computers in them will not increase the compression, or advance the timing enough to take advantage of that higher octane fuel, so there is no real benefit.
The only small benefit would be from the additional detergents, emulsifiers, etc. that the fuel company may include in their higher octane fuel, and not in the lower octane versions. You can get pretty much the same benefit by running a injector cleaner or some other kind of fuel additive thru the tank every now and then instead.
The only small benefit would be from the additional detergents, emulsifiers, etc. that the fuel company may include in their higher octane fuel, and not in the lower octane versions. You can get pretty much the same benefit by running a injector cleaner or some other kind of fuel additive thru the tank every now and then instead.
The CT6 is an improvement over previous design but it still carries over some old stuff that's hideous. That proposed engine sounds amazing, though.
bunnspecial
macrumors G3
Just some more ramblings on oil(thick or thin) reaching the necessary parts of the engine...
If you've ever driven a car with a carburetor and points ignition, you probably know that if things are in proper tune the engine can start with just a tap of the key. Of course if things are out of tune(as they often are) all bets are off, as well as in temperature extremes. I'm often amazed at how easily my MG starts when it's warm, and it's not at all unique in that respect. A 4 cylinder might take a half rotation of the crank to start, while a V8 can start in even less-there again if everything is right.
By contrast, fuel injected cars will almost invariably start every time regardless of the conditions, but most take a few rotations before they fire. On my MKZ, the engine will spin 2-3 times then start even if I only tap the key.
I suspect that this is by design. The single largest amount of force on the engine rotating parts occurs on the rod bearing of the cylinder on its power stroke, and the main bearings closest to that rod bearing handle a lot of stress as well. By contrast, the load on the bearings is relatively tiny during the other 3 strokes, and also quite tiny on what would be the power stroke if the engine isn't actually running. This is why-in the MG world-we spin the engine without plugs to build oil pressure after major surgery-pulling the plugs reduces the bearing load to only the friction in the bearings themselves and of the rings against the walls, while with the plugs in there is a bit more load from compression.
A computerized engine can spin the engine without injecting fuel or sparking. This would give oil a chance to circulate before the real loads on the engine start, and I suspect this is what's happening. I would also guess that it's probably squirting fuel to prime the cylinders, and then starts firing the plugs after a couple of rotations.
Again, I'm sort of talking out my rear end, but it all makes sense to me and if that's the case it alleviates concerns over oil circulating before the engine is really under load.
If you've ever driven a car with a carburetor and points ignition, you probably know that if things are in proper tune the engine can start with just a tap of the key. Of course if things are out of tune(as they often are) all bets are off, as well as in temperature extremes. I'm often amazed at how easily my MG starts when it's warm, and it's not at all unique in that respect. A 4 cylinder might take a half rotation of the crank to start, while a V8 can start in even less-there again if everything is right.
By contrast, fuel injected cars will almost invariably start every time regardless of the conditions, but most take a few rotations before they fire. On my MKZ, the engine will spin 2-3 times then start even if I only tap the key.
I suspect that this is by design. The single largest amount of force on the engine rotating parts occurs on the rod bearing of the cylinder on its power stroke, and the main bearings closest to that rod bearing handle a lot of stress as well. By contrast, the load on the bearings is relatively tiny during the other 3 strokes, and also quite tiny on what would be the power stroke if the engine isn't actually running. This is why-in the MG world-we spin the engine without plugs to build oil pressure after major surgery-pulling the plugs reduces the bearing load to only the friction in the bearings themselves and of the rings against the walls, while with the plugs in there is a bit more load from compression.
A computerized engine can spin the engine without injecting fuel or sparking. This would give oil a chance to circulate before the real loads on the engine start, and I suspect this is what's happening. I would also guess that it's probably squirting fuel to prime the cylinders, and then starts firing the plugs after a couple of rotations.
Again, I'm sort of talking out my rear end, but it all makes sense to me and if that's the case it alleviates concerns over oil circulating before the engine is really under load.
quagmire
macrumors 604
The Camaro turns over a few times before it starts up when cold. This is believed to allow the fuel pressure to build up. A member of that Camaro forum I go on posted measured fuel pressure before the injectors sprayed fuel into the cylinder which seems to support that theory. But that oil theory also makes sense.
It’s the longest startup of any car I’ve experienced even those with DI.
It’s the longest startup of any car I’ve experienced even those with DI.
A.Goldberg
macrumors 68030
That’s a terribly confused rear end. It don’t think the area decklid quite works with the angular trunk/bumper theme. The back of the car is way too sloped, I think a more upright line would be more appropriate as the angular theme over exaggerates it. The horizontal, inner parts of the tail lights doesn’t quite fit and I don’t like the bends in the horizontal silver trim. And for all the hard angles of the car, I’m surprised they went with round exhaust ports.
That said, I do like the front. The side profile reminds me a bit to much of the STS or something though- it’s too boxy and looks very dated, whereas the front and rear look far more modern.
bunnspecial
macrumors G3
In my experience, that's not abnormal to get a V8 going. My LS needed to crank once it hit 40º or so outside too. The Town Cars wouldn't crank quite that much, but then the 4.6L modular in those is lower compression and tuned more for comfortable cruising than power vs. the little 4L V8 in the LS.
I would be skeptical of it being a fuel pressure issue. The fuel supply line is usually kept at close to working pressure anyway, and I suspect that if it needs to "top up" pressure it happens as soon as you get the key to the on position.
BTW, on the keeping the line under pressure thing-anyone who has ever opened a fuel line without disabling the pump can attest to this 🙂 . When I change a fuel filter, I pull the fuse, start the engine and let it die, and then crank it a few more times to relieve pressure in the fuel line. My dad once had a fuel filter changed at Jiffy Lube(not a good idea) and they re-used one of the old line clips-a few days later it failed and left a nasty mess of gas.
quagmire
macrumors 604
The low pressure fuel pump may keep the pressure up when the key(or button) is turned, but the high pressure fuel pump is mechanically driven by the camshaft.
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Apple fanboy
macrumors Ivy Bridge
My first car had points and was an absolute dog to start. I was always fiddling with it to try and get things running better. But at 17 I didn't have a clue. No internet back then, so just a Hayes manual.
I wrote it off eventually with a bit of help from a colleague.
I've got some Chiltons! I think most garages and dealers now use digitized services.
Perhaps that’s what I am attracted to the CT6-V Sport, is because it is different overall. The rear is slightly obtuse. I think the rear bumper facia is a little overall two squared, which could be more rounded , but with the tail lights having the LED light rope at least matches the front of the vehicle headlights with a similar LED extending pattern downwards. I mentioned before, I’m not find of chrome accents and I don’t like the chrome strip on the back of the trunk, but Cadillacs are Notorious for chrome trim pieces throughout the vehicle, especially surrounding the grill.
I really appreciate the wired mesh grill, but again, being this is a sport model, the chrome accent could be deleted or blacked out. The headlights when you first look at them are different, but the more I see, the more I like them. I can tell you the first thing I would do if I owned that car, is I would change those wheels out immediately. I think those wheels are extremely dated and are not very unique to a six-figure car.
Overall, I Think the CT6 V Sport is a distinct combination of both luxury and a performance Car.
Other Details about the CT6 V Sport:
- 10 Speed Automatic
- Brembo brakes
- Magnetic Ride control
- Active Exhaust Control
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Yeah, GM's [recent] design language is very odd, there's a discordance that's like a vehicular uncanny valley 😀
AustinIllini
macrumors G5
Honestly, the latest Chevy offering (Malibu, Impala) always make me go "wow!". I love their designs. Just wish the Impala had proper driving wheels (rear)
Now that the Chevy SS has been discontinued from the Holden Paltform, I would absolutely be thrilled if GM ever [re-introduced] a Chevy Impala SS. If they did, I’m sure it would be some for sort of V6/turbo charged model, but to bring back the naturally aspirated V8 in a sedan would be stellar. Highly doubtful given the efficiency and power with smaller turbocharged variants in today’s market.
bunnspecial
macrumors G3
The big problem with a revived Impala SS is that the current platform is front wheel drive. High powered front wheel drive cars sound bad on paper, and in my experience drive even worse.
I know Chevy has done it in the past with both the Impala and the Monte Carlo, but it doesn't change the fact that-IMO-those cars are less than thrilling to drive. Cadillac has a long history of front wheel drive V8s too in the Deville range and El Dorado(including the massive 500 CID in the El Dorado), but those were meant to cruise comfortably and not necessarily meant for high performance driving.
I go back to the front wheel drive V8 with which I have the most driving experience-the Lincoln Continental. Even though that's not a super high powered engine, almost everyone needs a bit of practice to be able to drive one without chirping the tires and torque steer is absolutely terrible if you mash the gas. Plus, the turning circle is atrocious-it's roughly the same as the Town Car of a similar vintage, and the Town Car is a MUCH larger car.
Since I missed the boat on buying a new SS, I'm waiting for KSP to start surplussing their Caprices. When they do, I'll probably try to buy one at auction. Of course, there's always the used route on the SS, but I've seen few if any used ones for sale, and I don't know that I'd find the exact configuration I want(specifically a manual trans).
I know Chevy has done it in the past with both the Impala and the Monte Carlo, but it doesn't change the fact that-IMO-those cars are less than thrilling to drive. Cadillac has a long history of front wheel drive V8s too in the Deville range and El Dorado(including the massive 500 CID in the El Dorado), but those were meant to cruise comfortably and not necessarily meant for high performance driving.
I go back to the front wheel drive V8 with which I have the most driving experience-the Lincoln Continental. Even though that's not a super high powered engine, almost everyone needs a bit of practice to be able to drive one without chirping the tires and torque steer is absolutely terrible if you mash the gas. Plus, the turning circle is atrocious-it's roughly the same as the Town Car of a similar vintage, and the Town Car is a MUCH larger car.
Since I missed the boat on buying a new SS, I'm waiting for KSP to start surplussing their Caprices. When they do, I'll probably try to buy one at auction. Of course, there's always the used route on the SS, but I've seen few if any used ones for sale, and I don't know that I'd find the exact configuration I want(specifically a manual trans).
The G8 GXP was another outstanding option in 4-door, V8 (LS3) vehicles that were offered in a manual. When Pontiac was cleaning house, a friend of mine scored one for like $12K off MSRP (though his is an auto).
I was actually surprised at the bang-for-the-buck of the Charger (yes, I was lurking on the Dodge site ...). Start with a Scat Pack (the lowest cost package that includes the 6.4L Hemi/SRT), add the Dynamics pack (adds Brembos, upgraded black wheels, better tires), the Tech pack (also adds the driver pack) which is all of the safety tech (BLIS, ACC, front warning, etc.), upgrade the audio ... just under $43K for a 485HP, 4-door cruiser, lots of room, looks great, loaded with features/tech (the new FCA 8.4" headunit is outstanding).
I was actually surprised at the bang-for-the-buck of the Charger (yes, I was lurking on the Dodge site ...). Start with a Scat Pack (the lowest cost package that includes the 6.4L Hemi/SRT), add the Dynamics pack (adds Brembos, upgraded black wheels, better tires), the Tech pack (also adds the driver pack) which is all of the safety tech (BLIS, ACC, front warning, etc.), upgrade the audio ... just under $43K for a 485HP, 4-door cruiser, lots of room, looks great, loaded with features/tech (the new FCA 8.4" headunit is outstanding).
I remember those. I saw multiples of them between the recession and, as you said, Pontiac closing down. Surprisingly, I don't see as much of them as I used to. Garage kept?
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You should be in their commercials. 😛
crjackson2134
macrumors 601
Hey, thanks for the invite! Currently I’m a Mustang enthusiast, however I own a few fast cars. I’m not rich, so my cars probably aren’t particularly impressive to many here so I’ll do more reading and learning than posting.
My current fixations are on 4 of my newest acquisitions.
2x 2014 Mustang GT Premium Track-Pack cars (both black, MT6 cars)
2x 2018 Nissan 370Z nismo cars (both black, AT7 cars)
A.Goldberg
macrumors 68030
Agreed. A whole bunch of power in a FWD is pretty unremarkable.
My mom’s ES350 back in the day (2009 model was decently powerful with a 0-60 in 6.5, not bad for the day). Besides the cloud-like mushy suspension, the torque steer, though not worst I’ve experienced, sucked. Even if the suspension was tightened up substantially it will never have the same dynamics of a RWD car, especially with the weight distribution imbalance.
Even my girlfriends Volvo S60 T6 AWD with the now discontinued but impressive 3.0 6cyl turbo (~300hp, 0-60 in something like 5.5) fails to have anywhere close to the same dynamics as my similarly powered 535i xDrive as the AWD is rear biased in my car and FWD biased in hers. Luckily the newer generation FWD-biased Haldex system will route power to the rear under heavy acceleration (in addition to front slippage of course)- which negates torque steer, making it a a bit more sporty than a lot of other FWD-biased AWD systems these days. But if you’re cruising around bends at a relatively constant speed without overly pushing the throttle, you might loose that RWD push. And because the AWD is front biased, the weight distribution is something like 60/40 F/R creating massive understeer like any other FWD car.
Unless Chevy/GM can somehow manage to make a true RWD or rear biased AWD system for something like an Impala SS, I think it will be a pretty dismal “performance” vehicle.