# Starting Your Car....... **URL:** \ **Category:** Factual Questions\ **Created:** [March 17, 2002, 3:50am UTC](https://boards.straightdope.com/t/starting-your-car/98694 "2002-03-17T03:50:55Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![cornflakes](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@cornflakes](https://boards.straightdope.com/u/cornflakes)\ **Post date:** [March 18, 2002, 3:52am UTC](https://boards.straightdope.com/t/starting-your-car/98694/21 "2002-03-18T03:52:08Z")
> [@](#): > > \*Originally posted by cornflakes \* > See post above… > [@](#): > > \*Originally posted by David Simmons \* > \*\* > > I didn’t say anything about super-slick oils, or after-market additives or other market gimicks. Ordinary motor oils contain wetting agents and additives to improve the “cling” quality in addition to chemicals to counter the buildup of acids and other contaminating products of combustion. Motor oil isn’t just petroleum and hasn’t been for a long, long time. \*\* Which was probably why I replied to someone else’s post, not yours. That person offered something as helpful advice which was unfortunately not a good idea, at least my country’s government and the manufacturer of the main ingredient in the aformentioned additives advise against the use of teflon as a lubricant additive. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [March 18, 2002, 4:47am UTC](https://boards.straightdope.com/t/starting-your-car/98694/22 "2002-03-18T04:47:43Z")
somewhat of a highjack here about engine rpms… my redline (2 liter, 5 sp. manual, Mazda engine) is 7K. So far (in only a couple of months, and this is my first car with a tachometer), I don’t think I’ve pushed it over 4K (at 65 on 5th gear, it runs at 3K). Should I be pushing my revs closer to the redline before shifting? Am I losing efficiency somehow? Long term, am I limiting the engine’s ability to perform at higher revs? ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 18, 2002, 5:02am UTC](https://boards.straightdope.com/t/starting-your-car/98694/23 "2002-03-18T05:02:52Z")
yojimboguy’s questions: _Should I be pushing my revs closer to the redline before shifting?_ No. _Am I losing efficiency somehow?_ No. _Long term, am I limiting the engine’s ability to perform at higher revs?_ No. ---
**Author:** ![SirRay](https://avatars.discourse-cdn.com/v4/letter/s/cc9497/32.png) [@SirRay](https://boards.straightdope.com/u/SirRay)\ **Post date:** [March 18, 2002, 3:11pm UTC](https://boards.straightdope.com/t/starting-your-car/98694/24 "2002-03-18T15:11:14Z")
Once (if?) hybrid vehicles become common, won’t most engines be subject to instant start-up/shut-down quite often (indeed, at every traffic light, if I read the various proposals right)? ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 18, 2002, 3:50pm UTC](https://boards.straightdope.com/t/starting-your-car/98694/25 "2002-03-18T15:50:20Z")
Yes, SirRay, vehicles are being designed as you describe. We need to clarify what most of us assumed from the totality of the opening post, but hasn’t been specifically stated–we’re discussing starting and driving a COLD engine. Warm engine starts are not a concern. ---
**Author:** ![xash](https://avatars.discourse-cdn.com/v4/letter/x/c6cbf5/32.png) [@xash](https://boards.straightdope.com/u/xash)\ **Post date:** [March 18, 2002, 11:35pm UTC](https://boards.straightdope.com/t/starting-your-car/98694/26 "2002-03-18T23:35:53Z")
**yojimboguy** , i mostly shift just before the red line… it won’t do your car any harm to continue driving at 4k rpm, but you won’t get to enjoy the sound of the engine at 7k and for me it’s just not as much fun driving at low revs as it is at high revs… also, your car might have an auto cut-off at the 7k mark wherein it cuts your engine down to 5k or so as soon as you cross the red-line… maybe you could take it to 7k just to see if it incorporates this feature… [very slight hijack] i’d like to ask whether turning on the airconditioner when you start a cold engine puts any additional strain on the engine ? and whether i should hold off turning on the ac until my engine warms up ? [/very slight hijack] ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [March 19, 2002, 12:14am UTC](https://boards.straightdope.com/t/starting-your-car/98694/27 "2002-03-19T00:14:06Z")
> [@](#): > > \*Originally posted by DVous Means \* > \*\*if you are paranoid about engine wear on starting, use a third party product like Slick 50 or Nulon. > > These are added when you change oil and are circulated with a running engine for about half an hour. What they do is deposit a microthin film of Teflon to all surfaces that the oil contacts, thus reducing friction and wear. Hence there is some protection in place when the engine is stone cold and all the oil is in the sump. > \*\* And you wanna know what else it does? The Teflon coats the micron-sized passages in your oil filter. **Not good** for two reasons: 1) Some passages may clog up, thus reducing flow/increasing back pressure, 2) Passages which are not clogged will be more “slippery,” and thus allow some particles to get through which would not otherwise. I would _never_ put that crap in my engine… ---
**Author:** ![Niobium\_Knight](https://avatars.discourse-cdn.com/v4/letter/n/bc8723/32.png) [@Niobium\_Knight](https://boards.straightdope.com/u/Niobium_Knight)\ **Post date:** [March 19, 2002, 12:29am UTC](https://boards.straightdope.com/t/starting-your-car/98694/28 "2002-03-19T00:29:13Z")
I used Slick 50 in my last car’s engine. This was before I found out it isnt recommended. I’m sure I noticed a difference in acceleration (the engine seemed to rev a bit free-er). But I wouldnt use it again after what I’ve heard. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 19, 2002, 1:06am UTC](https://boards.straightdope.com/t/starting-your-car/98694/29 "2002-03-19T01:06:15Z")
> [@](#): > > \*Originally posted by xash \* > **i’d like to ask whether turning on the airconditioner when you start a cold engine puts any additional strain on the engine ? and whether i should hold off turning on the ac until my engine warms up ?** It gives the engine some more work to do, but it doesn’t stress it in the manner we’ve been discussing in this thread. There’s no need to wait to turn on the A/C. In fact, in many cars the defroster automatically engages the A/C compressor because it helps dehumidify the air. Now, if the car has been parked in the sun in hot weather and it’s hotter inside than outside, you do want to wait a few minutes before selecting “Max A/C” (most American cars) or “Recirculate” (most Asian cars). Those positions draw air from inside the vehicle. After you’re getting some coldness from the A/C system, this enables getting really cold air. But if it’s drawing in 120 degree air from inside the car instead of 90 degree air from outside, it’s just going to take longer to get cold. Start off with the “Normal A/C” or “Fresh (outside) air” position. If you have a car that selects between outside air and recirculated air, use the “Recirculate” position only for maximum cooling of the air conditioner. In the “Defrost,” “Vent,” and “Heat” modes, the systems work best with outside air. [Previous page](https://boards.straightdope.com/t/starting-your-car/98694.md?page=1)