Hi, have a 2001 C320 with 90'000 miles on it. I"ve changed the spark plugs, catalytic converters and obviously oil, but not much else mechanically.

I have read on these boards that a new thermostat may increase mileage. If that's true, it's a no brainer. Morever, the TPS sensors tend to fail before 100k so I might replace that out of caution.

Do the EGR valves need to be cleaned? My basic question, is what parts need to be cleaned/replaced to get optimal gas mileage?

thanks,
Ben

 

make sure all your filters are clean including fuel filter, air filter, and pump those tires up. but most important focus on the alignment of the rotors etc that could be affecting gas mileage. empty the trunk and be light on the gas pedal. i have heard much about cold air intakes on mercs but maybe one could benefit u.

 

Clean the throttle body and MAF

 

Hey guys,

I've done all the basic stuff like change all the fluids, belts, spark plugs, alignments.

In 90,000 miles, I have changed the fuel filter once.

Short term I plan on changing out the thermostat, changing air filters to K&N or similar and a new Throttle position sensor if thats really necessary. Also, I plan on adding new spark plug wires.

Any other parts or procedures you guys would recommend?

 

Hi,

Is this aftermarket thermostat okay to use on an 2001 C320 M112 engine? I read on another thread that a member paid $130 for a genuine Mercedes-Benz part.

http://www.amazon.com/Stant-14569-Th...ar=1&carId=003

 

Use Parts.com and get the real MB thermostat for ~$50.

 

Thanks for the tip. I didn't see a Mercedes-Benz part number so i'll e-mail them. $25.80 for a legit MB genuine replacement thermostat is a good value.

http://www.parts.com/oemcatalog/inde...layCatalogid=0

 

I've only been getting 205-230 miles per tank on a 2001 C320. Obviously this is an extremely poor results. I use Techron every 5000 miles. I'm feathering the throttle in my old age, but living in the city, my commutes are roughly 10 miles (5 miles each way) with a weekend 52 miler (26 each way) off to the countryside.

I like to think that I maintain the car well, but going on 11 years, some deferred maintenance is inevitable.

Here are a list of major changes that could affect gas mileage since 2007 and 2010.

2010
-Tires (inflated to 35-40 PSI)
-Brake pads/discs
-4 new shocks, springs strut bearing caps (front).
-New Control arms, thrust arms, end links +suspension bushings. sway bar bushings also
-Alignment
-Tranny flush

Since 2007
-Air Filter
-MAF sensor
-catalytic converter(s) (warranty)
-brake fluid
-coolant flush
-spark plugs (Denso Ik16)

Here's a list of things I plan on swapping out over the weekend:

-Engine air filters (K&N)
-MAF sensor cleaner spray (from Autozone)
-Spark plug wires + visual inspection of plugs)
-Crankshaft position sensor ( preventative maintenance)
-Fuel Filter
-Thermostat (no CEL but hoping for improved performance nonetheless)
-cabin air filter (engine bay + passenger footwell) First time in 11 years!

I'll report back on any MPG changes, in the meantime, if ya'll have any suggestions on stuff to do 'While i'm in there', please chime in.

thanks!


PS. I just did some price shopping and found Bosch equivalents for plug wires and CPS which will save me $100.

Bosch 09848 spark plug wires are $88.94 at Amazon, $80 cheaper than NGK wires

Bosch crankshaft position sensor at Autohausz.com at $54 (including shipping) which is about $20 cheaper than Beck Arnley part at Amazon.

With those savings, i'll be getting some Bosch 9652 Iridium plugs. Summit Racing offers them at $5 a pop with free shipping. After $2 per plug rebate, that works out to $36 for 12 plugs!

 

you can get better MPG by changing your driving habit...

for the last month or so i've been driving slower on the fwy at 70mph vs 80mph. my mpg in the c32 improved to avg around 18mpg up from 16.8mpg for the last 2k miles when i reset it. i've also been doing the same in my C350 as well as when i drive my sis's CLK320. the 350 and the CLK are both getting around 20-21mpg avg now.

 

i don't think I could be any gentler. There's a stoplight every couple blocks with mostly stop and go traffic so she never gets a chance to breathe. 5 miles of this and a picture starts to develop. Hybrid cars get the best mileage out of commutes like this.

 

All of the Parts.com Mercedes parts orders are filled by a MB dealer in the Midwest.

 

Strapped in K&N Air filter, cabin filter (engine bay+passenger footwell) and MAF sensor spray cleaner.

Immediate boost in MPG. After resetting the MPG 'After Start' menu, I drove 5 miles around the block and even after flooring it twice to 80MPH, I achieved 22MPG, on this jaunt. Usually, I would be lucky to crack 17.5mpg on this loop.

On the way back into the city (26miles) I hit 25.8mpg 12 miles in whereas normally, i'd be lucky to hit 23.5mpg by mile 20.

instead of first removing the MAF sensor to clean, I sprayed it directly into the intake even while engine was on. Engine bogged down and it took quite a few more cycles than normal to crank over when restarting engine.

Only after did I read the instructions and learn that sensor should first be removed. Over the next few weeks, i'll clean out the throttle body, spark plugs+wires.

I'll take a picture, but i'll be returning the passenger footwell charcoal activated filter by MANN for OEM. The MANN filters are pleated while the OEM part made by Helsatech A203 830 0418 are a solid porous structure and are noticeably heavier.