Maybe this should be in the technical help forum, but my roommate and I were wondering why old cars (he's got a 1966's mustang and I've got the 190SL) require warming up for a few minutes before driving, but new cars can be driven right after start up. For both of us, if we start up our older cars and go ahead and put the car in gear, it stalls out almost immediately or is too sluggish to drive. But our newer cars can be put into gear right after starting up. What accounts for the difference?

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Hemant

'57 190SL
'86 560SEC AMG

In a word, any way.
The engine managements computers of modern cars with their battary of sensors, solenoids and motors, Can detect, analyse and adjust to a huge range of conditions that would cause an older car to stall out till its warm. The older mechanical controls are less precise and after many years of use, have hundreds of places where wear can effect their performance. ie throttle shaft wear that doesn't keep it from working but just 'less well'.

Being a nostalgist though, I'd have to say its because new cars lack character.

Mark

I like your answer Mark! Cars form the mid 80's (my roommate's Chevy van, and the 560SEC I've been borrowing) drive right after start up, and I don't think computers were in cars at the time that those were built. Both of these newer cars actually have more mileage on them than his mustang. Does anyone know if when his mustang was new and my 190SL was new if you had to wait for the car to warm up before driving? What's happening in an engine that is different when it is warmed up and when it is cold? Just pondering, Hemant

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Hemant

'57 190SL
'86 560SEC AMG

According to the 190SL Owners Manual, they recommend AGAINST letting the car warm up. They say drive it away right away, but not hard. I remember reading this when I
was looking for something earlier this week in my manual.

And yes, mine runs like cr@p until warmed up.

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Bill Streep
San Antonio
'57 190SL (toy)
'08 S5500 (mine)
'09 CLK550 (wife's)
'06 SLK350 (daughter's)
'11 GLK350 (daughter's)
'03 CLK310 (spare)

You could drive the Mustang. Dunno about the 190 - those were few and far between in Seattle in the '60's.

Being old enough to actually have driven cars of this vintage in their time ('59 Corvette, '65 Impala, '64 Impala) and having ridden in lots of others, I can say that the advice was to start them and drive. Not to waste fuel warming up.

As long as the choke was working - generally it was a coil nestled in the intake manifold that opened the choke as it heated - they were fine. Idle cold was around 1000 RPM.

You got in the car, and gave the gas a single "pump" to reset the choke. Started the car and drove.

It was not until the early 70's when emissions got tougher, but catalytic converters were not available, that cold start and warm-up became an issue with American cars. During that era, they were leaned-out with timing retarded and used air pumps to recirculate unburned fuel. Warm-up running was awful and performance suffered.

After the "cats" came in the the late '70s, things got better, and the computers and FI arrived in the '80's.

Chuck

'57 Chev Bel Air
'57 Chev 2 dr wagon
'59 Corvette with 283 dual quads
'64 Chev Impala 250 hp 327
'69 Chevy II with 325 HP 327
'61 Austin Healy with Chev 327 V8
'72 Vega (got married)
'72 Mercedes 250c (got job, moved to DC)
all MB after this except for two Porsche 928's

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe