johntypes

I installed a mugen stat,cap,fan switch and since then I have had a drop in my gas milage is this nomal ,my drop has been 4 mpg or could I have another promblem please HELP

CleanCL

iTrader: (4)

i cant see those causing gas mileage to go down. i would check into the more obvious, PCV valve and EGR valve.

typeR

they defintetly could... the lower temps specially in winter will cause you to run richer

Paclark01

Absolutely correct. I think those upgrades are really beneficial if the car is supercharged or is in a constant warm climate, or both. Like in Arizona.

ChucksCL-S

But running cooler is better for the engine, right?

CleanCL

iTrader: (4)

i'm running them and even in the coldest winter climates here in NY i've never thrown a CEL.

Zippee

Maybe, maybe not.

In general going a bit cooler will increase the density of the fuel/air charge and give more power BUT every engine has an optimum operating temperture and that's where you want to be for best performance. Going cooler or hotter would depend on what that temp is for your engine and where you are running now.

It is easy to get below the optimum temp.

johntypes

MY Milage drop 9 mpg on the highway I usually stay at 72mph I went from 34 mpg to 25mpg It hard for me to belive that much would change

Paclark01

The car would most likely not show a CEL on the dash. Just a drop in fuel mileage would be the only indicator. Usually, if the engine temp is too low the car would run rich. Especially when the weather is cold, a significant drop in mileage could be possible.

CleanCL

iTrader: (4)

only reason i said that was because people HAVE thrown CELs in the past. i forget exactly what the codes were, but it had something to do with temperatures being too cool.

typeR

oh you can throw a cel...when i was on my spoon 160 i would some times ...cooling system inefficeincy something like that ...there's a certain amount of time the expects to reach op temp and if you dont you will throw a cel

RaviNJCLs

iTrader: (4)

Holy shit. That's a lot.

I had them on for about a year before I parted out. In fact I installed them right before the winter. I saw nothing but gains in my MPG. I think there may be something also going on here. Can you tell that your fan is coming on at the lower temps? Could it be that it's not working right and it's coming on at warmer temps? Any spike in the temp gauge?

fuzzy02CLS

iTrader: (2)

I don't know. I don't keep track of gas mileage.

johntypes

the fan is coming on as it would nomaly

Allout

I'm in CA and I ocassionally throw a CEL for Temp. It's randon when it happens.

With your upgraded radiator, the need for the Mugen mods is less. I've always felt that these mods were to compensate for the limited capacity and recovery time of the radiator over multiple hard runs. The HP gains with this mod were seen on multiple runs if I remember correctly. The first run was fine. Subsequent runs suffered because the cooling system couldn't recover quickly enough. Lowering the temp and fan switch effectively gave the cooling system more running room before it became heat soaked.

mrsteve

iTrader: (1)

My first CL-S never had a problem in the winter or any time for that matter with the Mugen mods.

My second CL-S used to throw a code once a month so I un installed them after the S/C'er came off and sold 'em.

BigLizard

Since I installed mine I've never thrown a CEL. Washington's winter weather and spring weather has been quite cold. I have noticed that the engine runs richer from the these mods. I've been watching my mileage since I installed these and the mileage is down signifigantly from what I normally get. I used run about 350-375 miles @ 14 gallons before I installed these. Now I'm somewhere around 315-330 @ 15 gallons.

Oh well...thats the price you pay for modding.

lowlt1

I did a LT1 vette swap in a pickup i had with a 160 stat in it. Thinking like everyone else the cooler the better. Then I read a post on a LT1 forum saying that if the pcm hasn't been program to 160 then your MPG will drop. Because the comp. tries to keep the motor at the running temp of 180. I switched to a 180 and it did seem like the motor was running smoother and the MPG got better. I know its a different motor and pcm but I figure it could be the same with these cars. I don't know...

mrsteve

iTrader: (1)

If the motor was trying to run hotter it would run lean not rich.

Allout

Depends. In some cases, cold temp triggers additional fuel. On a cold start, it richens the mixture like a choke on a carburator. That's part of the reason why cars throw most of their emmissions on cold starts.

mrsteve

iTrader: (1)

Good point. I did have that problem once on my first CL-S.

Glasuan

When you swap in a lower t-stat, the fans never come on, till 180 degrees. Thats the reason for the fan controller.

johntypes

Could it be the purge valve