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Drew Dowdell

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Everything posted by Drew Dowdell

  1. Because we have become much dumber as a society.
  2. I have not liked the Malibu since it went to the new short wheelbase model. I do not like the 2.5 engine, it's torque feels very soft at the low end compared to the old 2.4. I would get her first choice and then go to the Impala only if you can't make the deal work on the Lacrosse. Distant 3rd would be a 2.0T Malibu.
  3. The Enclave competes with the RX precisely because it offers a 3rd row. These are the "grandparents" cars.. and then they go shopping they like the RX, but the Enclave gives them the same luxuries but also offers a 3rd row for the grand kids. The RX is the most traded in vehicle when people buy a new Enclave. They are similar enough in their size segment that they compete. Buick will also be going after the 2-row segment as well, so it will be double trouble for Lexus from Buick. The CLA and the 300 aren't even remotely similar in size
  4. If your career allows it, move to one of the more expensive areas of the country that has a growing population.
  5. If you're able to make predictions like that with any sort of accuracy, what are you doing being a power train engineer instead of a commodities trader? Diesel and gasoline regularly trade places for being the higher price fuel. Diesel typically costs more than gas in the winter and then they swap in the summer. There are occasional exceptions to that trend, but it is generally true. uh, yeah, it does fluctuate, of course. But plotted out over the last decade, Diesel has been higher on avg....hence my remark. And of course I could be wrong. it's a prediction. Diesel also gets better fuel economy, so the higher cost is usually justified. When it costs less, it's just gravy. The current Cruze isn't the best example to look at because the diesel is actually a more powerful engine than the gasser and thus doesn't get the far and above increase in fuel economy that it would if it was of more similar output. The new 1.6T diesel I would expect to have a more compelling fuel economy case. In the Astra, it is rated for 63mpg highway in Europe. While I think that is probably a tad optimistic, even if they hit the very high 50s, that will be a great success.
  6. It feels like a Chinese knock-off of the Avenier
  7. If you're able to make predictions like that with any sort of accuracy, what are you doing being a power train engineer instead of a commodities trader? Diesel and gasoline regularly trade places for being the higher price fuel. Diesel typically costs more than gas in the winter and then they swap in the summer. There are occasional exceptions to that trend, but it is generally true.
  8. It was the German automotive press that came up with that term, not GM, and I'm guessing that it just didn't translate well.
  9. You need to make up your mind: Do vehicles compete on size only and no other factors? Do they compete on price only and no other factors? Do vehicles compete only if their parent brand overlaps in the segment in each and every model and only on that factor? Or...could it possibly be more nuanced than that?
  10. The only things you have countered with have been demonstrably false, vastly out of context, or irrelevant to the discussion. NHV - modern pushrod engines are no less smooth than DOHC. The 3900 was butter smooth. MPG - They meet or beat DOHC engines of similar output VVT - They have it. Emissions - They meet regulations Power delivery - Pushrods deliver the power lower in the RPM range Packaging - Always smaller than a DOHC engine, always weigh less when the same block material is used.
  11. You could argue that, but you'd still be wrong. We're talking about cars in the same segment here. Two brand that don't fully overlap can have cars in the same segment even when others of the brand do not. Whether Lexus likes it or not, Buick has at least two vehicles that compete directly with two of their products. I'm not a product planner at Buick, but they must sell at least enough of the low end trims to justify producing them. Even if it's 3/4 premium trims and 1/4 non-premium trims, why would you give up those sales?
  12. Not if there is no more room to upsize. In sedans, 3.6/3.7/3.8 seems to be the upper limit for DOHC engines. We're not talking about race cars here. We're talking about the every day cars that people drive.... the Ford Fusions, the Jeep Cherokees, the Honda Civics. All of the cars that rarely crest 4,500 rpm on any given day. Cars that are being sold with 250hp in big numbers and @ 6500rpm in tiny print at the bottom. It's the Honda Civics that you have to wind up to get them to go. Everyone (except race car drivers, which we aren't talking about anyway) would do better with engines that made their torque at low RPM. If that wasn't the case, Ecoboost wouldn't have a reason to exist. Good points. Let me just add this. Boosting does of course give you power down low, because that is where the turbo sizing/cam selection is optimized. Of course. But in regards to NA engines, rarely does a V6 gain in package volume enough to make a difference, going from let’s say a 3.0L to a 3.5L or even a 3.5L to a 4.0L in a SRX or what not. A few mm in bore and stroke, has a small impact. That story changes a bit with a V8, yes, because those few mm get multiplied more due to extra pistons. But a 6.0L Coyote can be made to fit in a Mustang, of course. It’s just sheet metal at that point. But again, everything has to be considered, including fuel economy, etc. And as far as power delivery subjectivity goes, I made that remark based on years of debate about what matters most to people. Hence the subjectivity. Yes I know torque down low is awesome, and so too is a long cam pull on the top end, which I also love – which goes back to my original topic of contention….having both is best. We're not talking about 0.5 liters of displacement difference. We're talking a full liter or more. A general rule is that in the space you use with a DOHC engine, a pushrod can have 50% more displacement. So where the max size for a DOHC engine is 3.0 liters, you can fit up to 4.5 liters of pushrod. Where you can fit a 3.6 liter DOHC (which is just about the max in packaging for a FWD sedan) you can fit at least 5.4 liters of pushrod engine. Back in 2005, the 3900 was equivalent in max power to the 3.0 DOHC engines of the day... and had much broader torque delivery to boot. "Years of debate" on the subject and those on the DOHC V6 side of the debate have been consistently wrong. The charge has been led by the automotive enthusiast press who liked to wring the snot of their VTEC Civics. They would then write about how DOHC was just the bees-knees. They created this idea that DOHC was inherently superior in every application. They convinced the general public of it enough to demand it in their cars even though the general public couldn't tell the difference between a cam-shaft and a seat cushion. Unless you are specifically buying a sports car with sporting intentions, you are nearly universally better served by a larger displacement pushrod V6 than a smaller displacement DOHC V6. That last line is quite a stretch drew and a subjective opinion as well. Well, I've posted objective numbers. Perhaps you would like to counter? The GM 3900 produced more torque and over a lower and broader RPM range than a Toyota 3.0 of the same vintage. It did so while generally matching the fuel economy of the same engine. What held GM back in performance at that point was primarily the 4-speed automatic compared to the 5-speed auto in the Toyota. When paired with a 6-speed manual, the engine could really rock.
  13. Ford makes lots of passenger car diesels, they just don't see fit to sell them to fussy americans. I can understand their reluctance given this country's prior history with passenger car diesels. To be fair, at the moment everyone but the Germans are missing out on diesel passenger car sales.
  14. Depends on the market, but in most big cities, yes.
  15. Not if there is no more room to upsize. In sedans, 3.6/3.7/3.8 seems to be the upper limit for DOHC engines. We're not talking about race cars here. We're talking about the every day cars that people drive.... the Ford Fusions, the Jeep Cherokees, the Honda Civics. All of the cars that rarely crest 4,500 rpm on any given day. Cars that are being sold with 250hp in big numbers and @ 6500rpm in tiny print at the bottom. It's the Honda Civics that you have to wind up to get them to go. Everyone (except race car drivers, which we aren't talking about anyway) would do better with engines that made their torque at low RPM. If that wasn't the case, Ecoboost wouldn't have a reason to exist. Good points. Let me just add this. Boosting does of course give you power down low, because that is where the turbo sizing/cam selection is optimized. Of course. But in regards to NA engines, rarely does a V6 gain in package volume enough to make a difference, going from let’s say a 3.0L to a 3.5L or even a 3.5L to a 4.0L in a SRX or what not. A few mm in bore and stroke, has a small impact. That story changes a bit with a V8, yes, because those few mm get multiplied more due to extra pistons. But a 6.0L Coyote can be made to fit in a Mustang, of course. It’s just sheet metal at that point. But again, everything has to be considered, including fuel economy, etc. And as far as power delivery subjectivity goes, I made that remark based on years of debate about what matters most to people. Hence the subjectivity. Yes I know torque down low is awesome, and so too is a long cam pull on the top end, which I also love – which goes back to my original topic of contention….having both is best. We're not talking about 0.5 liters of displacement difference. We're talking a full liter or more. A general rule is that in the space you use with a DOHC engine, a pushrod can have 50% more displacement. So where the max size for a DOHC engine is 3.0 liters, you can fit up to 4.5 liters of pushrod. Where you can fit a 3.6 liter DOHC (which is just about the max in packaging for a FWD sedan) you can fit at least 5.4 liters of pushrod engine. Back in 2005, the 3900 was equivalent in max power to the 3.0 DOHC engines of the day... and had much broader torque delivery to boot. "Years of debate" on the subject and those on the DOHC V6 side of the debate have been consistently wrong. The charge has been led by the automotive enthusiast press who liked to wring the snot of their VTEC Civics. They would then write about how DOHC was just the bees-knees. They created this idea that DOHC was inherently superior in every application. They convinced the general public of it enough to demand it in their cars even though the general public couldn't tell the difference between a cam-shaft and a seat cushion. Unless you are specifically buying a sports car with sporting intentions, you are nearly universally better served by a larger displacement pushrod V6 than a smaller displacement DOHC V6.
  16. I'd really like to see a turbo-DI pushrod engine.... even do the 4.3 V6 Ecotec3. Probably looking at 430 lb-ft to 470lb-ft of torque.
  17. Not if there is no more room to upsize. In sedans, 3.6/3.7/3.8 seems to be the upper limit for DOHC engines. We're not talking about race cars here. We're talking about the every day cars that people drive.... the Ford Fusions, the Jeep Cherokees, the Honda Civics. All of the cars that rarely crest 4,500 rpm on any given day. Cars that are being sold with 250hp in big numbers and @ 6500rpm in tiny print at the bottom. It's the Honda Civics that you have to wind up to get them to go. Everyone (except race car drivers, which we aren't talking about anyway) would do better with engines that made their torque at low RPM. If that wasn't the case, Ecoboost wouldn't have a reason to exist.
  18. At the same displacement, yes. However, a NA OHV engine can be much larger and deliver more usable power than a DOHC engine of the same exterior packaging. It has been shown over and over again that marketing is more important than performance results. If moving to DOHC gets GM more sales due to marketability, then of course they should make that move... even if OHV engines would actually serve the customer better. GM is in the business to make money, and unfortunately, that means keeping HP/L whiners happy. (sometimes I really hate the automotive media, they have the majority of the responsibility on this issue) usable power is a subjective metric, or at least, an application specific one. And upsizing can be done by anyone. There is no reason why a 5.0L coyote valve train can't fit on a 6.0L. No it isn't. If the transmission forces an upshift at 6,000 rpm but the engine peak horsepower isn't until 6500 rpm.... you are OBJECTIVELY not getting the horsepower that the car is marketed at. But if I get my peak horsepower and torque down low, say around 4000 rpm, and the transmission still doesn't shift until 6,000 rpm, I get everything I paid for. You realize that if usable power was purely subjective there would be no reason for Ecoboost to exist. Ecoboost only exists as a replacement for displacement now that pushrod V6es are out of fashion. Ecoboost allows the feel of a big displacement V6 out of a small displacement I4, or a big displacement V8 out of a small displacement V6. The very existence of Ecoboost crushes your argument that horsepower is more important than low end torque. Anywhere you can put a 6.0 DOHC, I can fit a 9 liter pushrod.. or an 8.5 liter with a super charger on top. You can't get around the fact that DOHC engine just take up way more space than pushrod engines.
  19. You may be thinking of the 3800 as an old design. The 3500/3900 were not and they didn't have NVH issues like was said about the 3800. The 3800 was a 90 degree V6 and always had a bit of a balance issue. The 3500/3900 were new 60 degree V6es with variable valve timing, variable intake manifold runners, variable displacement (Impala only)
  20. Volkswagen sells 25% to 30% of each car line with a diesel under the hood.... that's a pretty great take rate and I'm sure Chevy wants a slice of that. Cadillac is going to offer a range of diesels in its cars too.
  21. At the same displacement, yes. However, a NA OHV engine can be much larger and deliver more usable power than a DOHC engine of the same exterior packaging. It has been shown over and over again that marketing is more important than performance results. If moving to DOHC gets GM more sales due to marketability, then of course they should make that move... even if OHV engines would actually serve the customer better. GM is in the business to make money, and unfortunately, that means keeping HP/L whiners happy. (sometimes I really hate the automotive media, they have the majority of the responsibility on this issue)
  22. Yes, but the Escalade also qualifies for Uber Black and Uber XL, which can charge higher rates. Since UberBlack has stricter requirements on age, mileage, condition, and brand, the acceptable alternatives will cost a similar amount. (Probably $30k - $40k for a used luxury sedan)
  23. So then GM made a mistake by switching to DOHC for their sedan/CUV line? Anyway, more displacement can be had by anyone, but in terms of making the air pump more efficient, they are pretty tight against that wall. We know this because of how hard they worked for to get more power out of the LT1, mostly using old hot rodders tricks for more airflow (CNC'n ports and chamber) and a stout bottom end that can handle a few hundred more rpms. And there is little by way of technology to change that any time soon. I am in the business deep enough, and an avid hot rodder, to know this mjuch anyway. And yeah, Ford was able to get a heck of a lot of power out of only 5.2L, but you will never see an OHV engine with a FP crank, because OHV is restricted to much fewer rpms. The limit of flow is a design choice. Multi-valve pushrod engine designs do exist and there is no reason they could not be included in modern engine designs. But the point that I'm apparently failing to make is that pushrod engines offer more usable power rather than the marketed power of DOHC designs. Who cares if your DOHC engine is rated to 300 horsepower if the transmission will never let you see that RPM? I have 160hp in my Honda CR-V, but I only get that if I rev the thing up to 6,000 rpm.... and trust me, it really doesn't like it. My Buick Encore has 138hp at 4900 rpm, but I also have 148 lb-ft of torque at 1800 rpm to 5,000 rpm. Though it has lower horsepower, the Encore actually feels quicker.
  24. And GM chose the DOHC route to silence critics like yourself and SMK who think HP per Liter is important. It is all marketing and all of the manufacturers doing it. Horsepower is an easy number to fudge since it is only measured at the peak. In the case of naturally aspirated engines, simply spin the engine fast enough and you'll make the horsepower the marketing department wants.... but us end-users rarely see that horsepower because it is so high up in the RPM band. Ford 3.7 liter DOHC - 305 hp at 6500 rpm (F-150) GM 3.6 liter DOHC - 305 hp at 6800 rpm (Colorado) Chrysler 3.6 liter Pentastar - 305 hp at 6350 rpm (Ram 1500) In all of the above cases, you'll never see that horsepower because the transmission will shift before you even get there. Now in that same space, if I'm not at all concerned about valvetrain layout.... I can fit a pushrod V8. GM 5.3 liter Ecotec3 - 355 hp at 5600 rpm (Silverado) OR 376 hp at 5600 rpm if running E85 Chrysler 5.7 liter Hemi - 395 hp at 5600 rpm (Ram 1500) So if you only have so much engine bay to fill... would you pick from the 3.6 liters or the 5.x liters above? What if you're looking for a small, lightweight engine for a sedan? Perhaps a Buick Lacross or Cadillac XTS... both of which have received complaints about soft low end torque.. GM 4.3 V6 Ecotec3 - 305 lb-ft @ 5300rpm GM 3.6 V6 DOHC - 264 lb-ft @ 5200 rpm Between these two engines, at no point in the RPM band does the 3.6 exceed the 4.3 in torque. Given that the 4.3 is physically smaller than the 3.6, which of these would you choose? Turbo charging brings in a new variable, but we haven't seen a turbo-pushrod since the 1990 Pontiac Grand Prix McLaren. A turbo-DI 4.3 V6 would be awesome.
  25. I have never had an issue with the NVH in the modern pushrod engines. As I mentioned, I drove for 20 miles with one in 3rd gear and never noticed anything until the fuel economy instant readout seemed relatively low. The OHV V6s could out-MPG 4-cylinder DOHC units from Toyota... and in 2007 the 3900 could produce highway fuel economy with a 4-speed auto nearly equal to the current PentaStar + 8-Speed of today. The 3800 was the first V6 to be ULEV certified and the 3500/3900 engines had VVT to improve emissions further. GM is not anywhere near a brick wall on their V8s. Due to the relatively small packaging of the pushrod V8s, they can simply increase the displacement. That's what the 6.3 is for... and they can go all the way to at least 7.0 if they need to. And that 7.0 will fit in the same or less space than a 5.0 DOHC. Probably the best comparison to make is the new GM 4.3 Ecotec3 V6 Silverado verse the GM 3.6 DOHC Colorado. Fuel economy is roughly the same (when adjusting for the heavier, squarer vehicle the Silverado is), Torque in the 4.3 is a good bit higher, but that is mostly tuning. And yet the 4.3 is physically smaller and lighter than the 3.6. Wherever you can put a DOHC engine, I can fit a pushrod engine with 50% more displacement. Every time I see a car with a 3.6 liter DOHC V6 in it... there is a little voice in the back of my head saying "You know, a 5.3 V8 would fit there with space left over...." GM has already done it.
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Drew
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