Slappy3243

http://www.dailytech.com/article.aspx?newsid=20925




So what do you guys think?

Darth Xed

My concern with buying a turbo'd car in a daily driver would be long term reliability / repair bills.

Obviously there is more to go wrong on the car vs a naturally aspirated engine.


I wouldnt have any issue leasing a car like this, but if it were something I was planning on keeping for 100,000+ miles or whatever, I'd think twice about it. This has been in my head, actually, ever since Ford announced the turbo'd V6's for the F-150.

94LightningGal

I just think said Mazda executive is saying this, since his turbo engines get such poor fuel economy.

With the technology on todays turbo motors (like the water jacket on the Ford turbos, that continue to circulate coolant AFTER the engine is shut down), I have no reliability concerns. The Ecoboost is a fantastic engine.

We had a 1987 Audi 5000S that had the turbo engine. It still had its original turbo, with 300K miles on the clock. That car still ran like a raped ape. It needed alot of things, but the engine/turbo was not one of the things wrong.

HAZ-Matt

He makes an interesting point about complexity. You certainly do get more complexity with the extra components. I don't know what he means exactly by "right-sizing." It all depends on if you are willing to sacrifice power or not. The point of forced induction is to increase power for the same displacement. If you could convince consumers that they don't need as much power as they are used to then you could go to smaller NA motors.

bossco

Boy thats tough when your used to a certain amount of performance (caveat; vehicles get lighter to maintain the same p/w ratios). When I had my 07 GT I used to think the folks around here where kinda crazy when they said a 300hp GT was slow, then I upgraded to a GT500 and its been down with clutch problems lately. I've been commuting in a A5 GT while I get the GT500 taken care of and you know what - folks around here were right! 300hp is really unimpressive

jg95z28

Bingo! Look at the old RX-7s. They were never known for their fuel economy. For some manufacturers, turbo means performance only... fuel economy be damned.

Z28Wilson

I didn't really understand that point either. He talks about "right" or down-sizing an engine yet he also says a 1.0L turbo wouldn't be right for the CX-9 either (obviously). He's kind of all over the place here.

guionM

On one hand, I understand his point about putting undersized, complex turbo motors instead of placing rightsized engines. If you go back to the 80s, many manufacturers were placing undersized engines in cars that looked great in EPA test cycles, but because those engines had to be pushed harder to do the same job another "right sized" engine might do just above idle, the smaller engine got worse fuel economy that the bigger "right sized".

He also has a valad point about complexity, and I'll add in weight. When you add in the heavier duty engine components, intercoolers, water and oil tubing and such, yes, that's a lot of added expense.... and weight.

But the point I think he's missing is that most all of us use power for brief bursts for acceleration and passing, yet very little to maintain highway speeds. Old undersized engines had to rev like mad using lots of gas. However, today's small engines put out far more power. In the 80s an 86 horse 4 in a Celebrity used plenty of fuel just keeping highway speeds. Today that same sized engine makes more horsepower than V8s back then on far less fuel than even the 4 cylinders did back then.

This is more than enough to move vehicles along on small engines without hurting fuel economy and with a turbo, have that sudden punch we've gotten used to over the past decade where all vehicles have gotten faster than the most power vehicles of the muscle car era.

I see what the guy's saying. But I don't think he's taking the whole situation in account.

BTW, Darth, durability isn't that much of an issue with blown cars. They use heavier duty parts today. Even back in 1989, parts for blown cars were pretty healthy when done right. Thunderbird SCs ran 12 pounds of boost (todays cars run 5-9). As long as you didn't muck around with the pulley, you'd have a long engine life. SRT4 Neons are also holding up extremely well, even with boost diled up a bit.

Z28x

I'm not sure what he means by right sizing. Ford and Mazda have a large range of naturally aspirated engines and all the EcoBoost engines with the equivalent amount of HP get better MPG. Ford, GM, and Hyundai turbo 2.0L engines all out perform their small V6 counterparts.

bossco

I've got to wonder if the stigma of reliability with turbo cars is a hold over from the early turbo days (well not like Corvair or Starfire early), but in the early 80's when manufacturers were strapping on turbos that just used the engine's oiling system to pull double duty as lubrication and cooling (seems to me without aftercooling as well on some models). While running down the road it wasn't a big deal since the oil was flowing through the turbo and engine but when alot of drivers got home, they pulled into the driveway and just shut the car down and the still very hot turbo would cook the idle oil clogging the bearings and leading to failure.

I remeber reading well about the need to let the car idle for a bit till the turbo slowed and cooled down to prevent coking in the bearings or employ a mechanism to keep oil flowing while the engine was off. All that seemd to go away with water cooled turbos and better oils.

TrackMagicWS6

I suppose this means Mazda will get rid of the turbos on their Diesel engines and upside them to V6's and V8's?

Slappy3243

The technique is still in use today. I think they are called Turbo Timers. Somebody correct me if I am wrong. I don't think it has to be done on stock turbo cars but a few years ago, my coworker had one installed in his Supra. The car was incredibly fast but you wouldn't really know it by looking under the hood. He dipped into the 9's during his fastest run. Anyway, his car had a timer which ran the engine for 1 or 2 minutes after the key was removed from this ignition to keep the oil flowing. You could still lock your doors and the car acted like it was off. It was pretty cool.

godofdragons

As long as the turbo/engine are well matched and tuned, a smaller turbo engine will always be more economical than an engine using displacement to get the same power.
However, I wonder how displacement on demand skews this.

I may also be a bit biased since I love how easy it is to get more power out of a preturbo engine :P

WhiteHawk

After seeing the torn down ecoboost at the auto show I don't think packaging is going to be an issue. Those manifolds were some of the smallest I have ever seen.

I always wondered how they got so much better economy, though. In all the boosted motors I have seen, they start dumping fuel as soon as you hit the boost - usually down into the 11:1's, and my 04 GTP used to get in the 10:1's from the factory.. It seems counter intuitive to me. I almost think they are exploiting a loophole in the fuel economy test, but the real world numbers prove they work.

-Geoff

bossco

Direct Injection is probably able to get the A/F ratios down a bit, especially in conjunction with after cooling.

For heavy footed drivers, I dont think there is a fuel economy advatage, but for the average driver, especially in city driving where using a down sized motor that doesn't really use any boost until you mash the gas it would wokr pretty good.

Well it seems that way around my AO anyways. The predominant driving style seems to be wait until the car in front of you rolls 15-20 feet then idle up to 15-20 mph and get caught at the next light - rinse and repeat - and on the highway that means get up 45mph and merge then gently accelerate to 60 in a 65 and cross over into the left lane