Best engine temp

[kickflipjr]

So what is the best engine temperature. I know most cars run at around 1/2 on the temp gauge. Under 1/2 is too cold (oil is to thick = lower mpg). Is 3/4 ok? I know being in the red (usually around 7/8) is bad and can harm the engine.

[diamondlarry]

So what is the best engine temperature. I know most cars run at around 1/2 on the temp gauge. Under 1/2 is too cold (oil is to thick = lower mpg). Is 3/4 ok? I know being in the red (usually around 7/8) is bad and can harm the engine.

I heard somewhere that the additives in oil don't really reach their full effectiveness until the oil reaches somewhere around 200 degrees.

[rh77]

I think that the hotter the engine, the more efficient it becomes (I just put a hotter thermostat in, so I hope it does). The hottest I could find was 192F which replaced the 170F stock version. But here's the kicker...

Most vehicle guages don't really display the "true value" of the engine's temperature -- I'd recommend a ScanGuage tool or datalogger to confirm the coolant temp output. The car's guage usually moves up to the "normal" position and won't move if the temp goes up 25 degrees, for example. It keeps the general public from watching the guage too closely and freaking out if it moves too much.

There has to be a "sweet spot" for engine temp. The hotter the better, but too hot and you get pre-ignition/pinging, risk of cracking the block, etc. Prolonged exposure to 7/8 of the "red zone" will wear out parts sooner and break-down oil sooner.


RH77

[chesspirate]

Because of driving conditions (long drive uphill) i changed my thermostat on my truck from 195 to 180. I did this to prevent overheating (wich seemed to be hurting my power going uphill).

I recorded no difference in mileage. (although my rig is a '91 and TBI, hmmm)

I've actually done a number of different tests and noticed almost no difference in mileage, (i'm always between 20-22mpg's.

[SVOboy]

I think rh77's recent luck with the 192 thermostat suggests that hotter is better, and I see no problem with it being this hot, or else they would not have built a thermostat for this temperature.

[diamondlarry]

I think rh77's recent luck with the 192 thermostat suggests that hotter is better, and I see no problem with it being this hot, or else they would not have built a thermostat for this temperature.

Here is another option too. It's kind of pricey but may be worth the benefits.

http://www.evanscooling.com/main1.htm

There's a guy on one of the Yahoo groups that is running this in one of his vehicles and he was able to find a 205 degree thermostat so he could take advantage of the special coolant. He did have to do some mods to his fan sensor so he could fool it into waiting until the temp got higher before it kicks on. I may look into this the next time I need to flush my system.

[MetroMPG]

fyi, the stock tstat in my metro is a 192.

and i know i've mentioned this in another thread, but consider running at least a partial grille block too: for quicker warm-up (not just the engine - the transaxle of a fwd car will run warmer too with reduced airflow into the engine compartment) and improved aerodynamics.

95% of my grille has been taped over since november. temps have been fine.

[SVOboy]

I had a radiator block on for a while, but it seemed to make the engine run colder, I think I'll try out a grill block though, can't hurt.

[Matt Timion]

I'm actually considering getting a smaller radiator as well. The 5th generation civics all had smaller radiators than the 4th generation civics (which I currently have). Since I am swapping in a motor from a 5th generation civic I could actually be doing more harm than good with my original radiator.

[SVOboy]

I'm actually considering getting a smaller radiator as well. The 5th generation civics all had smaller radiators than the 4th generation civics (which I currently have). Since I am swapping in a motor from a 5th generation civic I could actually be doing more harm than good with my original radiator.

Indeed, it is often said on honda-tech that efs (88-91 civics) had monstrously large radiators. Seems like a good and permanent solution. How much does on cost out of the junkyard?