I tend to drive around 70-72 on the highway in my 300sd. When it gets much above that, I start to get a little "engine resonance" (I guess you would call it that) that starts over 3100 rpm. It's slightly annoying on longer drives.

However, it certainly doesn't mind speeds of 80+when asked to do so...

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2014 Jetta Sportwagen TDI
1982 733i
2016 Frontier Crew Cab 6 spd.

We drive 70-80 depending on what highway speed limit is. We try to limit to 5 mph over posted in most circumstances. When it is wet, we do posted limit or lower.

I've had both cars over 100 on flat open, dry road out west. The CDI seems designed for sustained 100 mph driving

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-- Chris

'95 E300, 216k miles, Silver Surfer
'05 E320 CDI, 138k miles
'07 S550 4matic, 69k miles

Gone but not forgotten:

'76 300D, 350k miles?, SOLD in 1995
'75 240D, 300k miles, SOLD in 1991

Top speed for a W110 200D is 83 MPH and then the governor prevents it from going faster, plus the engine is already turning high RPMS. They will all do that speed unless they are worn out. I drove mine at 80 MPH almost the entire 14 hour trip each way from Washington to Utah and back except for breaks and lowered speed limit areas. I had no problem going up hills until I got to about 6,000 feet in Utah and then I started getting a lot of smoke going up a steep grade (6%, I think) and then I slowed down to about 40 MPH.

All you ever hear from people is how slow these cars are, but in my experience they are at least as fast as any other economy sedan or van on the road.

I almost didn't buy the 200D because of hearing all the stories about how slow they are and how you'll get killed if you try to drive one on the freeway. But, I bought it anyway with hopes it would do 55 MPH so I could get it home and then I'd only use it on rural roads. The freaking thing hauled butt and I was doing 80 in short time and left my roommate who was following me in the dust. Sure, you wouldn't want to race anyone in it, but I NEVER found it to be deserving of "slow". I have driven MANY slower cars that you never hear anyone complain about being slow.

I used to smile when I would fly up hills at 70 MPH and maintain speed while Toyota Camrys, etc. were struggling to keep up.

Here's a short clip of me driving it through Utah. I was only doing about 70 MPH here because I didn't want to be messing with a camera while driving in the fast lane.

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Stop paying for animal enslavement, cruelty, and slaughter. Save your health and the planet. Go vegan! I did 18 years ago. https://challenge22.com/

DON'T MESS WITH MY MERCEDES!


1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles

Our '81 240D will go a bit over 80MPH, but it's pretty loud inside so 63MPH with the AC on sitting behind a Semi seems to be the best choice. I couldn't imagine going cross country in this thing, it would take FOREVER!

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1981 240D Four on the floor, Orient Red over Parchment, bought with 154,000 but it's a daily driver and up to 180,000 miles, mostly original paint and all original interior.

While I have pushed 90+mph in my '81 300D ('84 trans/engine), the noise generated inside the car is quite obnoxious, especially if you have the windows down (A/C not currently functioning). It will do 70-75 no problem, but I feel like I'm in best control of the vehicle no higher than 70.

Of note, I think these cars (including my family's old '75 300D) were designed to be great cruisers (best mileage, too?) at almost EXACTLY 55 mph. Remember, that was the speed limit back then, and IIRC, both speedometers had a yellow highlighting on them at the 55 mph mark. The '81 feels in total control of the road at 55; as you approach 60, the noise and the car seems to feel a bit "unsure" of itself. I remember this being the same from when I drove both these cars as a teenager.

All of your newer cars were designed to run the autobahn at a minimum of 100 MPH for hours at a time. I've had new VW TDI's on the autobahn at 140 several times, though the fuel consumption is pretty aggressive at those speeds.

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1983 W123 300TD US spec Turbo engine, with Euro bumpers and manual climate control, and manual transmission.

A couple questions about that:

1. 50 inches of boost is about 24 and a half psi. Your sig shows a W123 300D. Are you really running that much boost in that car, or did you mean 50 inches of absolute manifold pressure?
2. Do you actually have a gauge that reads in inches of mercury? If so, where'd you get it?

My 300D is rather a lot faster than a 200D, and it's still slow. What cars have you driven that are slower than a 200D?

It wasn't the Camrys that were struggling. It was the drivers who are afraid of the accelerator pedal. A four banger Camry that's running right will accelerate from 70 up a fairly steep grade when floored.

Edit: I watched Squiggle Dog's video and then it came up with a recommendation for Visio Racer's "10 of the Smallest Car V-8 Engines Ever". Nice.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

I have three diesels.

On my 300D, it keeps up with traffic and I generally don't push it unless I feel like going fast. I've never had a problem with passing or going too slow and I can always keep the right speed on hills.

On my motorhome, I tested my 0-60 at about 37 seconds. This is with a 3.9l Isuzu diesel. At 13,000 pounds I can command traffic around me. On flat ground, it may be faster than a 240D, maybe...

On my VW Tdi, I have had a few times at least where I fear not being able to accelerate fast enough. On my recent trip through Washington, there were at least a few hills where I could not maintain speed. Still, it is faster than a 240D, but at 90hp I drive it like I am trying to steal it.

Dkr.

yes i have run 50" over atmospheric boost before and will be running more soon once my new pump is in. however for now im running 50" absolute cruising at 85 the waste gate is set at 75" HG absolute right now. my boost pressure gauge is actually a dual manifold pressure gauge from an aircraft with the first indicating manifold pressure and the second exhaust drive pressure (around 62-68" @ 50" MAP). mind you im running a holset HE221W with a 7.5 cm housing the stock waste gate spring on it was originally 28 psi turned that down after having some fun for a bit with the sounds it made.

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1985 300D om617: 8mm M pump 175cc 5200rpm, holset he221w @ 30psi, large A2W ic, compounds on the way.
KD9AFT
A&P

Having driven those old Diesels on dozens of interstate trips, I can second you that they are plenty capable of running top speed for long stretches of time. The shortfall I typically encountered was old radiators causing the engines to run hot when going up hills. Due to that, and an effort to minimize fuel stops and maximize fuel economy, I usually keep to around 60. But if I'm in a hurry, I can (noisily) do 75+ with no trouble so long as it isn't too hot outside.

My 220 Diesel has seen over 40,000 miles of long distance (1500+ miles each way) road travel under my ownership. Despite its advanced age and very advanced mileage (400K+) it has never had any problem on long distance travel. Those old "Fintails" and W115 chassis vehicles are the definition of "extreme reliability".

The only problem I've had with slow acceleration is waiting a little longer to make left turns on some busy roads. That's not really much of a problem when everything else is considered. Once those cars are up to speed, they'll stay there all day without a complaint!

129.6083. Exactly. So far......

Or, 117.8 on the Dodge/Cummins, though not on a daily basis.

Dan

When I had my variable vane hooked up I'd drive it like a crappy v8. I could keep up with most camrys

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

I tend to use slow throttle build at nighttime to avoid leaving smoke bombs, my car is excellent on the freeway, and easily does whatever speed I need, but from stop to stop its a bit of a chore, just cause I dislike creating smoke screens. My turbo is pretty old though so once thats refreshed, im sure ill use the full extent of my throttle then. that and my transmission gearing isnt adjusted right so I have to power up into 4th or slow down to avoid clunking into 4th when going down hill or up to a stop sign. Just another R&R ill turn into a chance to upgrade and update!! (and clean and repaint)

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A junkyard is not for junk

I have owned and driven 6 MB diesels over the decades and my kids still drive 2 of them. Yes safe and solid.
My new ride is a 2015 ML 250 bluetec with the 4 banger diesel engine.
I have put 45K miles on since new and I have to say it's the best MB diesel I have ever owned. It drives like a dream and has power to spare at low revs.
I think it's a combo of the 7 speed tranny and the twin turbo engine. A touch of my foot on the pedal and it kicks down a gear and kicks ass up to 4000 rpms.


I have a 5 mile up hill highway stretch on my way home where I regularly hit 100 mph when no ones around and I think the engine is under 3000 rpms.
I am a safe driver too.


jz

Drive how you like, just don't nanny it to the point you clog it up with carbon etc.

A 1978 NA 300D will do 100MPH And probably more if the governor let it
I got a speeding ticket in the '77 the other day so...

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1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
1975 FJ45>HJ45
1981 200>240D (to be sold...)
1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD