A1EK

I regularly travel each week on a 3hr journey between cities for work of 160 miles each way . My work offers a hire car but I much prefer my clk as its a perfect tourer on long journeys and so comfortable.

Just thought I'd show you the decent mpg if you stick to around 65mph... of 40mpg!

Williams707

OMG

MarcusF

Out-Standing.

A1EK

However , unlike most of you lucky Americans I only have the 230 Kompressor, as fuel is just stupid prices in the UK as it still costs me about £80 to do 320 miles like this. ! Pretty much every one I know drives a diesel these days .... im old skool with petrol !

City Rat

Great mileage, sadly I currently seem to lack the discipline on long highway trips and hover between 75-80, more often on the 80 end though.

A1EK

Just out of curiousity what does it cost to fill your tank? for me its about £85 I think

City Rat

Just about $50 or so. Not a cheap date if I took long road trips more frequently.

A1EK

I HATE THE US !!! thats £30! nearly 3x cheaper, so unfair !!? the last time prices were that low, I was too young to drive, and that was a while ago ! no wonder you go around in big V8 etc !!

Scott Simoncic

It has to be cheaper here, our Mass Transportation System is basically non-existent, and everything is so spread out.

A1EK

I know I have travelled through parts of America.... Boston, Chicago, Penslevania, Florida, LA, Vegas, San Diago..... Damn big place !

I could fill my tank by just working less then 1 hour !

City Rat

Just curious aside from discipline with the skinny pedal what if any.engine mods have you done or engine maintenance routines do you follow?

A1EK

Just reaching 150K now, I've not done too much but heres a list of things I can recall:

1. Changed MAF
2. Changed O2 sensor
3. Replaced breather pipes to inlet manifold
4. Thermostate

Servicing items:
1. Denso Irridium plugs every 4 years or so
2. K & N air filter , life-time
3. Mobil 1 fully synthetic 0 - 40W change at least twice a year.
4. Oil filter once a year
5. Fuel filter avery 5 years

I would say the engine oil is the most I change as its the life blood of the car, and is satisfying when its replaced with lovely new oil.

The most noticable difference I had with mpg was changing the thermostat as the car heats much quicker.

alexyates

Hi,
I've just done 2505 miles driving down to the South of France for holiday. I have a 6-speed manual and the economy is amazing. I was fully loaded with luggage, 2 people and a dog and from Blackburn down to London I averaged 48mpg (doing about 67mph on the sat nav, 70 on the clock) and by the time I hit the French riviera (doing 80mph through France and a stop off over night) I averaged for the full 1100 miles 41mpg. At the end of the holiday over 2505 miles I averaged 38.8mpg. Mercedes reckon that the manual pumps out the same 0-60 and mpg as the auto, they're talking out their backsides, probably to steer people into having an auto.

A1EK

I always thought that manual was quicker on 0-60mpg and better mpg and think your right.

I used to live in West london and due to the joys of the North Circular and hanger lane etc etc (Sorry for those in the US, its an area of busy road i London) I ended getting a sore knee from changing gears all the time so got the auto.!

MarcusF

In a car with lower torque capacities, a manual can be faster but that's because one can rev and slip the clutch. On a car with higher torque, the manual loses the only advantage it had - the standing start. Once rolling, regardless of the torque rating, manuals will lose ground with every shift and the manual will have to be shifted at least once between zero and sixty. I'm sure I have the 722.6 specs somewhere, but can say from memory that the 722.9s (7G-tronic) shift in 150 milliseconds while in "comfort" mode. They shift even faster when the loud pedal is planted on the carpet.

alexyates

7G-tronic is on the newer cars and more advanced so probably will be better but IMO it's only the new dual dry clutch autos that can compare with manuals. Another note, mines a cabriolet so I'd expect the mpg to be even poorer than the coupe due to weight and drag.

A1EK

Well it seems that despite the convertible you get good mpg, so enjoy the ride !

rorf

Driving like a hooligan I get a constant 10l/100km - not bad for a 3.2 litre engine. On the open road cruising at 130 km/hr for long distances then gets down to 8l/100kms.

Fantastic cars these CLKs

MarcusF

I've owned a few cars with manual transmissions, and I can assuredly state, like automatics, all manuals are not created equally. My Porsche's manual was good; pedal feel and clutch engagement were both good, the pedal wasn't overly stiff, yet had good grip (because there was no torque), but the shift linkage left a lot to be desired. The shift linkage in my Rx-7s felt notchy (good), but pedal feel was crap and it took an aftermarket lightweight flywheel / clutch / flywheel to make the transmission worthwhile. Even then, gear spacing was poor and pedal feel was never up to snuff. I've had other high torque vehicles whose clutches performed like light switches. I've owned seven cars with manuals and my 7G shifts better in auto mode than any of them and the gear spacing far better. The 722.6 in my CLK is also better than any of the manuals I've owned. Of course, that’s just going by what "I've owned". I'm sure others have owned cars whose manuals were fantastic. For example, my older brother’s E-type had everything except gear spacing (that and his Jag was a temperamental diva).

I personally feel there is no comparison between a dual clutch auto and a manual. A dual clutch auto does everything better - except for the fact that they weigh a couple of hundred pounds more than a single clutch auto.

Lastly, the 7G will soon be old school. 9G-Tronics are the next wave.

A1EK

Heres a curve ball..... I am just coming up to 150K Miles, my auto gives me no issues, but do you think I should go fo the tranny flush as my car has the original transmission oil from factory? I know its supposed to be in for life , but i've read so many posts on the better smootheness with changing the oil.?

Thanks

alexyates

Hi,
I know it's different box, but I changed the oil on my manual last year and I'm just about to hit 150k. I don't know whether the manuals are "sealed for life" but the oil that came out was goosed. It was black with the viscosity of water. The gear changes are far smother since I changed it. Also, the drain plug is magnetic and looked like metal mickey with an afro so if nothing else you'll be removing any loose debris. I would definitely get it done.

MarcusF

It's a great idea to change manual transmission oil, and this is why; synchros.

Manual transmissions have engagement collars and the synchros are attached to both sides (each side is used for a different gear). When a shift occurs, the cone on the gear, which is male, slips into the cone shaped area of the synchro, which is female. The friction between the two is used to speed up the collar and the associated gear to match the rotational speed of the shaft so that both gears are both moving at the same speed before the dog teeth are engaged. Thats why you can shift gears - because the gears (dog teeth) are sped up or slowed down so they can engage. The only time the engagement collar and gear will stop moving is if the transmission's mainshaft is still (the car is not moving).

The important word in what I just described is "friction". That's how synchros work, by friction. Since synchros slide against each other, they wear. Depending on the driving style, they can take a long time to wear out, but the synchro rings still "wear". Synchros are commonly brass, which is non-magnetic, so magnets in the pan don't trap synchro bits. Those bits are suspended in the oil where they cause everything that's supposed to be lubricated (gears, synchros, and bearings) to also wear. Because synchros are brass, and brass is soft, the wear is minimal - but wear it does. It's true that trace amounts of iron ore are used to make brass, so they are technically magnetic, but I can say for a fact that in a Porsche 901 5-speed, a Ford T5, and whatever Mazda calls their Rx-7 5-speed, the brass ends up suspended in the oil.

The metal you see on your magnet is another good reason to change manual trans oil. Transmission gears are manufactured to turn one another. Early on, a wear pattern is set up. That "wear pattern" results in bits of metal that are worn off the gears. Those bits end up in the oil. Being magnetic, they'll stick to the magnet ...until the magnet is covered and then they'll just circulate through the transmission, helping the syncros and bearings wear out.

Lastly, although oil technically doesn't "wear out" - the additives do. Also, those metal bits that are suspended in the oil, they cause the oil to get hotter than it would if it were clean. The hotter oil gets, the thinner it gets. Oil thickness is measured in centiStokes, cSt, and when engineers design bearing clearances, that's part of the equation. When the bearing clearance is excessive, wear occurs. In most transmissions, its not a ton, but it does wear.

A1EK

This is very interesting especially for the UK as most people here prefer manual

Scott Simoncic

BTW, in my 430, I can get 23mpg in the city if I'm super easy on the throttle, and I mean super easy. I basically have to **** off every other driver, but last month I ended up having to drop a large amount of money on a home repair, and I didn't want to dip into savings, so I wanted to see how far I could stretch my tank.

gun4hire

You make over $50/hr and you are complaining about gas prices? lol

The average american makes somewhere around $12/$15 per hour.. So while you may pay 3x our gas prices, you make 3x the money. You probably also have to drive shorter distances, so you win!