GT4ish

Took my first of several longer trips planned in my 981 GT4. I drove 1000 miles round trip with some other Porsche owners and about 700 of those miles were highway getting to the fun roads.

Once the car was warmed up, I'd put it in sport mode even just cruising at highway speeds. Seemed that keeping water and oil temps in the 180F and 205F range, respectively, would be better on the engine than 215F / 225F with sport button off.

Is my thinking correct? Does anyone else drive in sport mode 100% of the time?




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RobC4sX51

Not sure if the coolant temp is effected by sport mode but oil temp certainly is. And if just cruising on the highway (not spirited curvy roads), I’d say leaving it in normal mode is probably better. The engineers designed it that way for one, and the slightly warmer oil flows nicely for the engine allowing for optimum conditions for things like mpg. Being in traffic or city street driving might be better in sport mode plus you get rev matching. Glad you enjoyed the drive, she can now be cleaned😎

GT4ish

Good point on the oil viscosity. This is my first Porsche (and Direct Injection engine) and it seems to run hotter than other cars I've owned. I realize it's, partially, related to efficiency and emissions.

She's all clean!

GT4_Rick

No knowledge about this but interesting points to consider though! I personally only use sport mode for the auto rev match function on track days and mountain runs. Otherwise I never turn it on. I always have the exhaust valves open though (unless there's a lot of highway driving involved then I cruise with valves closed).

Cyclman

I always figured hotter might clear bad stuff out better…

Miles3719

I have always had sport mode on from the moment I start the car to the moment I turn it off but all very good points. I just like it for the auto rev matching. It certainly affects both water and coolant (opens the thermostat at 80c I find), but also I find that when you change up gears it will hand the RPM at the right rpm for that split second to lets you get the clutch out

Say you are shifting from 2nd to 3rd and your RPM goes from 4000 to 2500, the engine will hold it at the 2500 for half a second or so, before then letting it drop all the way to idle. Anyone else noticed this or is it just me?

Last_935

I have a contrary opinion. I have always been taught that heat is the enemy of engines. I run my car in Normal mode until the engine is up to operating temp. This is so the auto rev match function doesn't over rev the motor when it's cold. Once the car is warmed up, I put it in Sport mode to maintain lower coolant temps. My feeling (unsubstantiated) is that normal mode's higher temps are there to meet emissions requirements - not for the benefit of the engine life.

GT4ish

I will have to pay attention to this. Can't say I've appreciated that.

This was my line of thinking on my drive. When running the engine for 4+ hours between stops for gas, I figure why not keep things cooler? Although, arguments for warmer engine (such as oil viscosity) is something I didn't think about. The other prompt was that this car seems to run much hotter than other cars. I'm used to seeing water temps 185-200 on the highway, but without sport mode, the GT4 run 215+ pretty consistently and in the 180s when in sport mode on the highway.

robotvoice

You want your oil temp above boiling to help burn of water and other contaminates. I would say use sport mode when you're driving "sporty" and normal mode for all other cruising.

NoGaBiker

I bought a great little gizmo from a Russian guy maybe 8 years ago or so, for a 991.1. Pulled it off that car when I sold it and put it on the GT4 and it works the same. You pop off the little side panel of the central console, by the shifter, and you have access to a wiring harness that is for every switch in the console, no matter what you have. There's a standard connector so you can lift the entire console off if needed; Simply unplug that connector and snap this guy's gizmo in between the two connectors, snap everything back together. Now the car will always restart with every console button in the same position it was in when you turned the car off.

So, I never have to even think about it -- Sport Mode and Loud Exhaust are always on as long as I left them that way, which I did. Wish I could remember the guy's name -- I was on the 991.1 forum at the time and he ran a little ad there I think.

DaveGee

Possibly Vlad at t-design?

DaveGee

NoGaBiker

Thanks -- that was it. I kept having "something Russian-sounding @ T-Stat" in my head, but couldn't make the transition to what it actually was.

T-Design Memory Module It works exactly as advertised and is super easy to install. Price has only gone up to 229 from 199 since I bought mine 8 years ago.

Granted, that's a lot to pay to avoid pushing a few buttons, I get it. But it feels REALLY good to beat the gubmint at this one.

GeoJoe

Thanks for this reminder on that mod.

I hit those two buttons every time. The rev matching in the GT4 is superb and you gotta have the exhaust note. The cooling is a bonus.

PS-GT4

100% of the time. Aside from rev match, Sport mode opens up the third radiator - The coolant and oil temps will drop significantly by design. Once in a while, I will run it without sport mode and let the oil go way over 212 to burn off any potential moisture,

El_Duderino99

Yup, definitely noticed this. It matches revs on upshifts as well as you describe.