Thousand mile trip in the new (to me) CDI....
 

We spent a week with some old friends near Greenville, SC last week.

Took the CDI this time.

Drove from Virginia Beach, VA. through Durham and Asheville, NC., to Pickens, SC. VA Rt 58 to I-85, to I-40, to I-26, then SC Rt 25.

Just under 500 miles each way.

MPG average was 48.1 on the outbound, 48.3 on the return.

Drove conservatively, speed limit or plus 5 mph, and my wife drove about half the trip each way.

No particular preps other than bumping the tire pressure to 38psi, and running the stock wheel/tire setup vice the 265/35-18 AMGs....

This car continues to amaze me.

At one point, I looked at the miles to go 'till empty and added that to the odometer, and the car had a full tank range of 980 miles. Not bad for a 21 gallon tank.

Jim

Don't tell that to the owner's of 2005 Prius'. They'd be lucky to get 45 mpg...

A 2005 Honda Insight with 5spd manual transmission would have beat you, but I'd rather be riding in the Benz...

Compare Side-by-Side

Not that I'm doubting...but how is that possible? EPA rating is 37 highway.

My opinion is that the test sequences used to arrive at the ratings are a "worst case" scenario, and I also suspect that they are biased against diesel engines.

I also suspect that some car makers focus on producing cars and trucks which will score as high as possible on the EPA test, but when the average Joe drives them in the real world, they won't get the EPA rated mileage because they are driven differently from the way the car was designed to get its best mileage. In other words, the typical driver's commute doesn't match up to the profile of the EPA test sequence.

My neighbors have one of each of those....a new prius and an old Insight. :rolleyes:

He's out there fixing/messing with that Insight on a regular basis. Seems like a lot of trouble for a plastic go cart :eek:

Someday I will have a CDI MB. :D

As it is my wife and I don't drive enough to notice much cost savings of a diesel vs gasser. I have my 190d for when I want to be frugal...

I can't get mine to deliver 37mpg unless I'm sitting stationary in the parking lot drinking coffee....

At 55-60mph the CDI is sitting right around 1500-1600 RPM, the instrument cluster reports MPG's in the 47-48 MPG range. It's been my experience that the cluster is 1-2 MPG optimistic over what the car is really doing - so it's generally getting mid 40's at that speed. I have absolutely no idea how the EPA arrived at 37MPG - but its way, way off from what I've been getting over the last 50K miles.

Same deal with my wife's GLK250, its rated 33mpg highway but it consistently returns 37-39 on the highway.

Go figure.

But believe it or not that level of economy isn't the most impressive thing about the CDI experience. The combination of the power AND fuel economy is just hard to believe.

The EPA test under-rates modern diesels. Our Passat is only rated for 40 on the highway in the EPA cycle, but if you keep speeds down it's easy to hit, and pass 50 mpg.

-J

Nice...wish it underrated MY diesels! :D

Generally in my experience diesels do better than epa estimates. Especially in recient times gas car milages are now falling far below the epa estimates.

Fifty five miles a gallon up her on the imperial gallon is a common claim by several manufactures on some of their gas cars.. You will never approach it with a tailwind going downhill though. Conservativly driven perhaps very low 40s.

I have no clue of why they are doing this other than to hinder diesel sales perhaps in some fashion. Sales taxes collected on fuel for most diesels are far less in general could be a major issue.

There must be some real bias against them at some levels in north america as the diesel car has gotten quite popular and may even dominate sales in some countries. My daughters new ford fusion had an engine break down. Ford is taking it's sweet time repairing it. I will suggest she dump it well before the warranty is gone.

She is in a fifty fifty rental car currently. Ford is telling her they want to investigate the engine. Car has less than six thousand miles on it and I suspect it has the 1.6 litre twin turbo. Ford also says it boiled its oil. I would not count an any truth here though from them. If that is the engine she has it is getting a bad reputation. Also the epa claim for fuel milage is way off till it broke. Not a little but a lot.

It does now that the EPA revised all their old numbers.

1992 300D 2.5 - 23 city 29 highway - 25 combined
Over 12,000 miles my dad has averaged 33mpg.

1987 300D 3.0 - 22 city 27 highway - 24 combined
Lifetime of the car my average is 30

1988 190D 2.5 - 26 city 31 highway - 28 combined
Over 21k miles my girlfriend has gotten 31 combined.

Not as good as a a CDi, but certainly a substantial improvement over the EPAs combined estimate.

Diesel are notoriously under-rated, and hybrids are notoriously over-rated. I suppose the same is true of astute TDi owners, but you'll find guys who know how to drive first gen, stick insights returning 70mpg on tanks, but that hardly represents the average. Most Prius and Insight owners I know report on average well below their EPA rating. Whereas I've never met a CDi owner who got 37 highway.

Our Corolla is underrated, too. We get 38-40 MPG doing mostly highway at 60-75 MPH, even though the EPA rating is 36 HWY.

I wish I could say that our GLK250 gets that sort of mileage :(

We have done just over 9000km since new. I calculate each fill up. With car loaded, we get in 30-32mpg range. Only 3 times out of 14 fill ups since new have we done better than the EPA highway figure. % highway of course varies, depending on getting to and from highway.

Recently for relatively short highway trips to visit MIL, unloaded, my wife has got up to 36mpg, but that is unusual. Display often says we are doing somewhat better. Hilly areas consume more - seems you lose more on uphills than you gain downhill.

We drive at speed limit plus about 10-20%. ~115-120kph (70-74mph) here in Canada.

Luckily for us, diesel is cheapest fuel up here. But not cheap!

Hey, you drove right through my neck of the woods! Great to hear you're car is doing well. I would love to have one.

Easy. The car does it by reporting cumulative miles per gallon covered in it's latest particular snapshot of time and miles. The onboard computer (IF accurate) reflects what Jim and I, and TylerH are reporting the cars do when on a cross-country run.

My CDI only returned 40.1 or was it 41.1 mpg on the only long Interstate trip it's been on; SanAntonio to Dallas, about 375 miles, driving it home from the dealer I bought it from. From there - the mpgs dropped precipitously as I got off the Interstate and on to the feeder road exit to my home. Were I to have driven more miles in that snapshot, the car would have quoted/reported even better mpgs, as the car's computer was increasing the mpgs calculated, the further I drove that day. You can watch it in real time as you drive on a CDI's instrument cluster. On surface streets - far different figure appear, as the car doesn't do all that well in the City, in stop 'n go driving with the CDI in my experience with it.

Different time era. Different methods used by the EPA to register mpg.