How bad is WOT for your car?

[demarpaint]

Originally Posted By: hattaresguy


To test on your car, aim to at the on ramp, start it and floor it.

How do you guys think stop/start works and hybrids work? The motors kick on and off and go on load constantly.

You guys baby these things to much, they don't need to be treated like they are made from glass.


Do that every morning for a few years and let me know how the engine holds up. I have a neighbor who lives directly across the street from me. Each morning he starts his Honda up and revs it to the floor. Fast forward 3 years, it's blowing blue smoke. He has a habit of doing this with all his cars as long as he's been living here and each one had a blue smoke trail a few years later.

 

[rslifkin]

Originally Posted By: demarpaint
Originally Posted By: hattaresguy


To test on your car, aim to at the on ramp, start it and floor it.

How do you guys think stop/start works and hybrids work? The motors kick on and off and go on load constantly.

You guys baby these things to much, they don't need to be treated like they are made from glass.


Do that every morning for a few years and let me know how the engine holds up. I have a neighbor who lives directly across the street from me. Each morning he starts his Honda up and revs it to the floor. Fast forward 3 years, it's blowing blue smoke. He has a habit of doing this with all his cars as long as he's been living here and each one had a blue smoke trail a few years later.


Heavy load on a cold motor will beat up the rings and cylinder walls pretty badly. High revs risk bottom end damage. There's a big difference in how WOT is handled when parts are warmed up and at their design specs vs when they're cold and not quite the right shape or size.

Personally, I take it easy (in the case of the Jeep, under 1/2 throttle and under 2500 rpm) until a few minutes after the coolant is showing full temp (to give the oil time to get warm). After that, WOT and / or high revs are fair game. At 163k miles, the motor still has great compression, etc. I last had the heads off it at 136k and the cylinder walls still looked almost new (still had cross-hatching, no detectable ridge, held MMO overnight with pretty much no leakdown).

 

[itguy08]

Originally Posted By: artificialist

WOT may not be so bad, because look at how many people had 1970s-1980s diesel cars, and used WOT very often because of the low horsepower? Benz and VW made such engines and they did last. Obviously I can't include GM engines here....

Also, many of the old compact cars with gasoline engines frequently needed WOT. My father told me about what it was like to drive a 1971 Toyota Corolla.


When your first car is a 1986 Mustang with a 2.3L 4 and 88 Blistering HP (and IIRC 114 lb-ft), the throttle has 2 settings. Idle and WOT. At 175k after abuse like that since 50k, she still started every time and idled smooth. Had the body and emissions controls not given way she would still be here with us today.

If Honda drivers are blowing blue smoke from WOT runs, it's time to buy a better car....

 

[Mr_Incredible]

I had a '91 F150 302ci V8 4wd. I got an emergency call to return home, but I was 250mi away.

It was a time of day when I could put on the flashers, get in the fast lane, and flash lights at respectful distance to get drivers to move over, please. My steady speed was about 85mph, 90 for a while. When the temp started to go up I had to slow down. Hills mattered during that drive, as the engine would heat up on them.

So, my answer would be...it depends on the vehicle. Low gear, not aerodynamic, bugs in the radiator, ambient temps would all affect duty cycle.

 

[gofast182]

High mileage, cold start, above redline, zero load, no airflow/cooling!!!!

https://www.youtube.com/watch?v=FtKgOk-j3Zo&noredirect=1

 

[IndyIan]

Originally Posted By: demarpaint
Originally Posted By: hattaresguy


To test on your car, aim to at the on ramp, start it and floor it.

How do you guys think stop/start works and hybrids work? The motors kick on and off and go on load constantly.

You guys baby these things to much, they don't need to be treated like they are made from glass.


Do that every morning for a few years and let me know how the engine holds up. I have a neighbor who lives directly across the street from me. Each morning he starts his Honda up and revs it to the floor. Fast forward 3 years, it's blowing blue smoke. He has a habit of doing this with all his cars as long as he's been living here and each one had a blue smoke trail a few years later.

Alot of the higher mileage 90's Honda's I've seen autocrossing do burn some oil, especially on and off the throttle near redline, but seem to be quite healthy otherwise.
Hard revving a cold engine though is never a good idea though.

 

[JHZR2]

Originally Posted By: hattaresguy
Originally Posted By: demarpaint
Originally Posted By: SteveSRT8

Many modern engines can protect themselves pretty well.

Does that include the guy who lives two minutes from the highway acceleration ramp and mashes the gas pedal to get on every morning in cold temps? That seems to be a question that used to come up from time to time in the past. Thanks!


Nah that's just a little toy motor with a few quarts of oil in it, and that's not 100% load at least not more more than a few seconds.

Lets see how this works with a big motor, full load in 10 seconds.



To test on your car, aim to at the on ramp, start it and floor it.

How do you guys think stop/start works and hybrids work? The motors kick on and off and go on load constantly.

You guys baby these things to much, they don't need to be treated like they are made from glass.


Yeah except that real engines including GTGs on ships take minutes or longer to warm and stabilize before load can be applied. CAT, Rolls, etc all say that. And that's the nature of the comment.

Put any of those "real" engines to full load too fast/too cold routinely will not do anything good for it. And the vendors who monitor the engines will void warranties in no time flat.