Golf TDI got 97 MPG!
 

For anyone sceptical about the official MPG figures of diesels, apparently someone managed an amazing 97 MPG in a Gold TDI recently. And it wasn't a short trip either, a cross continent road trip of 995 miles. Good going!

https://www.carbuyer.co.uk/reviews/re...d-fuel-economy

A better VW link with more detail.

https://www.volkswagen-media-service..._auth=3Dpr0nBA

Wow, that's great!

Yes and they will be replacing the DPF soon if they don't give it an Italian tune up to burn off the accumulated soot!!

I think it takes longer than 1000 miles to clog up!

One, once. A statistical anomaly. When several do it, I'll take notice.

Just because something is unbelievable, doesn't mean it didn't happen Charon. Maybe you should fly here and take part in the MPG Marathon, people getting close to 90 MPG over 2 days driving.

https://www.thempgmarathon.co.uk/the-results/

I think this high mileage third getting has to be on an overall downhill grade almost to the extreme. Does anyone have any information about that? I'm getting 61 miles to gallon on 23 mile drive into the city of Chicago but I think it's because it's mostly downhill. Driving an Audi A3 TDI. The best of gotten driving home is 47.

A 995 miles long hill? I don't think so! Haha! There are a lot of hills where I live too, great going down as you say, but unfortunately you have to go up them first which uses a lot!

I think the numbers are plausible. Just by driving a diesel quite slow can do wonders, which many times is a real challenge on good roads with +60MPH speed limits.

My best fuel up is around 54MPG going various speeds up to 65MPH but mostly around 45-55 and even some city driving included and even using AC some of the time. Automatic transmission, 177HP engine and 1,5tonnes of vehicle. I think those numbers can be improved.

I used to think that 45mpg was good, 50mpog amazing and only expensive new cars with very low mileage got any better than that.
Then at the beginning of last year, I needed a car that was taxed and had an mot. That was my only criteria. I spotted a fairly battered high mileage Seat Ibiza 1.9 SDi for £430 on flea bay.
It had tax and mot so I bought it. It's been good on fuel. Last june, I went to collect a kayak I'd bought on flea bay. It was roughly a 400 mile round trip. I'd filled up a week or so before and the gauge was showing just over half full. I set off on a Saturday morning driving at a steady 60-70 miles per hour. When I got there I removed the blow up single mattress from the boot, blew it up and then put it onto the roof, the kayak on top of that and strapped it all down using ratchet straps. One through the two open front doors and another around the hinges of the hatch back. The gauge was showing just under half way.
I was going to fill up when I collected the kayak, but after seeing how much I hadn't used I thought I'd see how far I could go.
I set off driving between 50 and 60 mph. I got a lot further than I thought!
The journey was between Bromsgrove and Great Yarmouth. I had managed to get back to the Coventry area on the M6 before my clenched buttocks couldn't take the stress of running out of fuel any longer and I pulled in to the services on the motorway. I brimmed the tank, as I had at my last fuel stop. When I got home and worked it out I had managed 67.7 mpg.
Considering I had done a couple of weeks of commuting and then nearly 200 miles with a mattress and kayak on the roof it makes me wonder how many miles I'd be able to go at a steady 50mph on the motorway?
The car was around 150,000 miles at the time and judging by the state of it hasn't seen regular servicing!
I'm prepared to believe a modern eco diesel could do 97 mpg. The question is, could my 14 year old non turbo shed of a car get anywhere near that?
I am regularly getting 60mpg out of it commuting the 20 mile round trip to and from work.
I put £30 of diesel in at a time which is around 22.57 litres and I get 300 miles plus before the fuel light comes on.
As this is only used for running around and commuting, I'm considering chopping the roof off and maybe lowering the top of the windscreen a couple of inches, removing the back seats and taking the roof line from the top of the screen straight back to the top of the rear lights. Then cover the rear wheel arches and widen the front wings to allow the front wheel arches to be covered. Remove the rear bumper and bring the tail straight down towards the ground, to produce a 'Kamm tail'. Add some bodywork to the front to smooth the air onto the front of the car. Also, i'll lower the car by an inch or two and add aluminium panels to the underside to smooth it all down.
I'd add a rollover hoop at the B pillars to add some protection as I'd replace the existing steel roof with either carbon fibre or fibre glass.
Does anyone else have any other suggestions?

They seem like extreme modifications to me, for a car worth very little (no offense!) It would be good as an experiment I guess, personaly I wouldn't go that far, i'd be looking into things like servicing it, flushing the engine out maybe and perhaps changing the wheels and tyres for smaller, economical ones and see what a difference that makes.

On my current tank im getting 68.4 MPG, used 3 quarters of a tank but i've still got 250+ miles left, like you I wonder how to get the best out of the liquid gold we put in the fuel tank! Im hoping with just 6000 on the clock, it will be breaking in soon qnd the economy will improve. As winter approaches, im connsidering changing my wheels to 15" with winter tyres as the 17" on there now alone use 5 MPG.

I'd start with minor, easy to reverse aero tweaks first; a grill block, wheel skirts, air dam or belly pan, etc. Also keep tire pressure at max side wall.

There are some ideas for more extreme ones at this site. https://www.aerocivic.com/
I've seen photos of Geo Metro/Suzuki Swift which had the passegner seats, windows, and roof replaced with a flat sheet of metal level with the hood.

97 MPG is not hard to imagine in a Diesel. Diesel Fuel gives a specific (fairly constant) amount of HEAT per Litre of Fuel Combusted. IF the AIR TEMPERTURE is kept constant, and As the Engine Heats up to Running Temperature (90C for Jetta TDI), then you keep the additional weight to a minimum, (Spare Tyre,Wrenches, Extra Fuel, 200# of mechanics tools, etc, Mother-In-law etc..) Even running over hill and dale, (max 5% grade), the only thing preventing excellent figures is how heavy the foot is. (Cruise Control is wonderful for the Expressway)

But remember this is AFTER the engine gets WARM!

While it is COLD, the Fuel, is being burnt to not only push the car, it also is being absorbed by the block and the Radiator.

This is the Big Advantge of Diesel over Gasoline, It Ignites at a Higher Pressure inside the chanber, but, it does so with a lower temperature, than Propane, or Gasoline does.

So, its not only the Heat that it produces, its the Mechanical energy, that is produced by the burning of the fuel.

IF the engines got better with the designs, you would see less waste heat through the Radiator/ Warm Cabin exchanger, and a better amount of heat converted to energy (mechnical) called Torque, applied to the driveshaft.(CV Joints on FWD).

It's too bad, Toyota, GM, Ford, Nissan, Honda don't produce enough of the 'Complaince Type' Vehicles for the rest of the world.

I'm waiting for the grand engineers to put a Trailer-Diesel APU in behind an Electric Vehicle for Extended Range, and a Tiny Battery to Just Absorb the amount of energy from slowing down approaching a stop, and be able to push the car to a rolling speed of 25 MPH.

Goodness knows, the politicians, will figure out how to TAX electricity for ROAD USE as high as petroleum products are today.

The 1% club will not worry either way, but the rest of the 99% are waiting for GM and Toyota to get their manufacturing acts together.

You've pretty much described a Chevy Volt. I would be curious to see what a Volt could do if it had a diesel engine.

Not quite a Volt, more a iMEV with a Ski-doo motor attached, Drive Farm Diesel (No Road Tax), and then Generate the 3-5 Kwh for the iMEV in highway mode.

Chevron already killed the high-Density NiMH Battery of a moderate capacity. May Stan Ovahinsky Rest in Peace, as he was the inventor that 'Won the CM competition" for the best battery at the time, for Automotive use.

But you are along the right track. If the Total Weight of the Vehicle Can be reduced (say with 1/2 the Battery pack of the Volt), and Detatch the Engine Part from the actual Cab, as a Range Extender would, you would no longer need to carry along the weight of the batteries, as they are being depleted of initial charge.

See EVP Tender

Chevy won't admit to using a Diesel engine in a start-stop environment, because the engine takes time to get 'Up to Temperature' so that the performance of the design is better than the gassers.

They also do not prefer to buy the licence to the BOSCH fuel pump to deliver the fuel to the injectors, they prefer to use their own patents, and design the chevy Cruze with only 1 interior option, (Black cloth) ,and only 1 transmission option (Automatic).

A good read (IF you are up to it) is the GM Ignition Report to Executive from the Lawyer Anton Valukas.

GMs Opel devision makes lots of Diesel engines, yet they are not imported to North America in quantaties yet. (Cruze Diesel has a 3-5% Build rate), meaning that 95-97 out of 100 cars are gasser's for 3-5 that get built for Diesel.

I suspect that the VOLT is a COMPLIANCE only vehicle, and they will not improve the batteries to last 10 years, until they have sold their last gassers and are at bankrupcy's door again.:banghead:

I get 80 mpg out of my 12 year old 206 1.4 hdi. I would say 97 mpg is quite possible from a modern diesel.

Don't forget these are imperial mpg figures, not US mpg figures. (97 mpg = 80 US mpg)

Oliver.

Extreme? Maybe. Cheap car? Most certainly.
You don't think I'd hack away like this with a car or your age?
How do you estimate your 17 inch wheels are costing you 5mpg?

I can't block the grill, I need air to cool the rad. I planned to widen the front wings to the point that they would cover the wheels when on full lock. I keep my tyre pressures anyway. The underside of the engine bay has a cover, so Seat have thought a bit about things...
I also plan to replace the bonnet(hood) with carbon fibre or fibreglass to reduce weight.
With the roof, bonnet and hatch all replaced with composite I'd be losing a lot of weight. That in itself should get me better mpg.
I'll be starting cutting next month as the Seat's road tax expires at the end of the month. I'll be switching over to my other car, a Land Rover Discovery. If ever there was a car that needs to lose some weight, THAT'S ONE!

I saw recently that a company in Germany is trying to create a network of stations with fully charged battery packs in a small compact trailer. You pay a fee to have your electric car modified to be compatible and then you drive away and when you are getting low, you pull in to one of their charge stations and pick up a trailer. It gives you power while charging your on-board batteries. When you arrive at the next station, you unhitch your trailer, plug it in to recharge, and collect another one, or not.
I suppose it is one way of making driving an electric car more 'normal'.
I think I'd be inclined to build my own trailer with a small diesel powered generator in it. Charge the car as normal at home, and when I needed to drive any distance, hitch up the trailer. As long as it was locked to the hitch and had a locked cover you could park up and leave it anywhere.
Alternatively, design some brackets onto the rear bumper and have the generator attach that way. It would make parking in town a lot easier without having a small trailer to contend with, but would be more of a handful to get on and off the car.

I didnt estimate it, im not that clever! Im sure there is a way of calculating it properly, but I cheated and looked in the brochure, they quoted the MPG figures for the smallest wheels and the biggest and there was a 5 MPG difference.

Do you live in a desert? The manufacturers over size the radiator for the extremes that most of cars will never see. But I should have been specified a partial grill block. Along with the aero benefit, it will also speed up warm up times.

The trailer with a fully charged pack in it sounds like a novel idea, but there is no way that it could reach widespread implementation, at least here in the US. It is bad enough that anyone out there can go out there and rent a Uhaul truck that has no experience or ability to drive a large truck.

I'd say that probably only 5% of the drivers in the US know how to drive with trailers. I foresee these things being involved in a lot of accidents as drivers don't think about their car being longer, and with the way drivers cut each other off now, when their car is 5 feet longer, they will hit the car they're cutting off. Also, backing up and parking will also be a challenge on these cars with the battery trailer... and we all know there's lots of folks that don't know how to park already. We don't need to make it more difficult.

The Long Ranger genset trailer for EVs came out in the early '90s.
https://www.tzev.com/2001_rxt-g_.html
While there isn't a solution for people that forget their vehicle is now 5ft longer, the designers did take parking a backing up into account. The trailer has computer controlled steering to help the driver there.

About ten years ago I was running a highly modified Land Rover 90"
It had 265 x 16 inch tyres. They were great off road but I was getting really bad mpg. A mate of mine suggested swapping them for some more 'standard' 235 x 16 tyres. The overall height of the tyres would be smaller, which in my mind meant I'd get less mpg. I was wrong. With the rolling diameter, it meant that at 50mph or so I was running higher revs but it was closer to maximum torque. With the taller tyres I was below max torque which meant I was always having to use higher throttle openings to maintain speed.
I ended up using the bigger tyres on another set of wheels for off roading.

On the Seat I'm running 165 x 14s, I wouldn't want to go any smaller than that as I quite like throwing it into roundabouts. Especially the big one near me when I'm coming home on the late shift :)

I thought it was just Land Rover that did that. I took the fan off my 1961 Land Rover. The only time the needle got near the red was after about an hour of dragging the roller around my gaffer's 3 acre paddock in low third. I'll give it a try this week and see what happens.

I agree, to a point. I think the main use for these were to get the driver between cities while travelling on major roads. Ironically, the shorter the trailer, the more difficult it is to reverse with. These things were only about two feet long and possibly light enough to drop off if you had to turn the car around in a tight spot.
I learned to reverse a trailer on the farm when i left school. I'd hitch up a tractor after work and go reversing between the trees in the orchard

Car manufacturers selling in North America have to consider the car could see Canadian winters or driven through Death Valley in the summer with the AC going full blast. I'm sure such extremes easily exist in other markets.

Factory wheel selections are matched to a tire size that ends up with combinations with nearly identical diameters. The larger wheels usually get worse fuel economy because they add to the unsprung weight, usually wider, and may be more performance oriented with higher rolling resistance.

Think of your wheels as flywheels, because in stop-and-go traffic, that's exactly what they are. Larger diameter wheels are not only heavier, they're heavier in the worst possible location: out near the rim, which exacerbates that flywheel effect. They're both harder to accelerate and to decelerate than smaller wheels are. So, larger wheels cost you the most fuel economy in city driving. What will cost you the most in steady-speed highway driving is wider tires (more rolling resistance). Unfortunately, larger wheels and wider tires often seem to go together. My 2011 VW Golf TDI 6-sped manual came with 225 tires on 17" rims. The U.S. EPA rated the car at 30 city and 42 highway. Before I took delivery, I replaced the car's wheels and tires with 205/65-15 LRRs. Over the life of the car (68,000 miles), it has averaged 44.6 mpg, and it will almost always better its EPA highway rating while driving in the city. It typically will achieve low-to-mid 50s on the highway (my best-ever tank was 56.7 mpg). I keep the tires inflated for even tread wear, not maximum fuel economy. My only driving concession to fuel economy is that, whenever it's polite to do so (no one behind me), I will coast to a stop in neutral. On a recent trip to the Colorado Rockies, we drove the car to the top of Pike's Peak (14,110 ft). When we stopped at the ticket gate at the bottom (~6,000 ft) on the way up, I zeroed out the trip computer. When we got to the top, it showed 31.9 mpg...which was the worst I have ever seen on this car, but it didn't seem too bad, all things considered. Of course, on the way back down it showed over 180 mpg...

That's pretty good going, especially for a US driver! Yea the 17" rims on mine use 5 MPG according to the tests, V's the 16", small change but a big difference. I am considering smaller rims, but I like to have a balance, I still like the car to look good ;)

I think you could do that downhill in a Ford Excursion. In neutral.

Yes, but finding that long descent where the engine will enter fuel cutoff mode and stay there for a while is tricky. Then if you consider the amount of fuel you have to burn to get to the top of that hill before you go down, its a wash at best. Certain vehicles excel in hilly terrain though. My Escape Hybrid does extremely well in the foothills of the mountains where you have long, rolling hills for miles.

If you read the full story, this was over almost 1000 miles. Try finding a hill that long please...

Europe, Japan, and I'm sure other ares has the manufacturers provide numbers for the different factory wheels.

Not required in the US, but Toyota did it for the Camry hybrid. Some of the complaints about the Fusion hybrid mpg could have been prevented if Ford had done the same.

...just joking. :)

Increasing your mileage is largely dependent on lots of little things added together with your right foot pressure on the pedal and your eyesight, timing to eliminate potential stoppage (known as inertia). If you live or drive in an urban setting, you are operating under adverse conditions to begin with, compared to the open road. At my age, hyper-mileage driving is too much work, but I do try to go "easy on the pedal" and avoid excess traffic if possible. Best of luck to those of you that excel in the challenge, you present us with worthwhile goals of preserving our resources. That's why I drive a TDi
Tenderfoot

It's true, hypermiling takes a lot of skill, patience and time, not to mention concentration. Easy on short trips, but to maintain it over an entire tank is almost impossible. Plus where I live, with only one lane of traffic going either way, driving in a slower manner would hold up traffic and annoy people. I guess its more tolerable in the states where most roads are highways so people can overtake safely without going into oncoming traffic!

It would appear someone else got similar mileage in a Honda estate in the MPG marathon this year.

https://www.nextgreencar.com/news/681...s-MPG-Marathon

Keyword being someone.

I highly doubt it under standard conditions. There might be variances where one engine will run better than the next engine off the assembly line, but not to the tune to that percentage over advertized efficiency.

So....I highly doubt it.