Golf TDI got 97 MPG! - Page 3 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 08-25-2014, 03:08 AM   #21
Registered Member
 
Join Date: Aug 2014
Posts: 10
Country: United Kingdom
Location: Worcestershire
Quote:
Originally Posted by CobourgVeeDubYah View Post
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.
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.
__________________

yfo866 is offline   Reply With Quote
Old 08-25-2014, 07:02 AM   #22
Registered Member
 
Join Date: Aug 2009
Posts: 2,486
Country: United Kingdom
Location: Mid Wales
Quote:
Originally Posted by yfo866 View Post
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 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.
__________________

__________________

Please subscribe to my YouTube channel
Draigflag is offline   Reply With Quote
Old 08-25-2014, 07:52 AM   #23
Registered Member
 
Join Date: Nov 2007
Posts: 1,460
Country: United States
Location: north east PA
Quote:
Originally Posted by yfo866 View Post
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!
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.
trollbait is offline   Reply With Quote
Old 08-25-2014, 08:24 AM   #24
Site Team / Moderator
 
Jay2TheRescue's Avatar
 
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,657
Country: United States
Location: Northern Virginia
Arrow

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.
__________________






Jay2TheRescue is offline   Reply With Quote
Old 08-25-2014, 11:20 AM   #25
Registered Member
 
Join Date: Nov 2007
Posts: 1,460
Country: United States
Location: north east PA
The Long Ranger genset trailer for EVs came out in the early '90s.
http://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.
trollbait is offline   Reply With Quote
Old 08-25-2014, 01:07 PM   #26
Registered Member
 
Join Date: Aug 2014
Posts: 10
Country: United Kingdom
Location: Worcestershire
Quote:
Originally Posted by Draigflag View Post
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.
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
yfo866 is offline   Reply With Quote
Old 08-25-2014, 01:10 PM   #27
Registered Member
 
Join Date: Aug 2014
Posts: 10
Country: United Kingdom
Location: Worcestershire
Quote:
Originally Posted by trollbait View Post
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.
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.
yfo866 is offline   Reply With Quote
Old 08-25-2014, 01:14 PM   #28
Registered Member
 
Join Date: Aug 2014
Posts: 10
Country: United Kingdom
Location: Worcestershire
Quote:
Originally Posted by Jay2TheRescue View Post
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.
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
yfo866 is offline   Reply With Quote
Old 08-26-2014, 06:53 AM   #29
Registered Member
 
Join Date: Nov 2007
Posts: 1,460
Country: United States
Location: north east PA
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.
trollbait is offline   Reply With Quote
Old 09-16-2014, 01:55 PM   #30
Registered Member
 
Join Date: Dec 2012
Posts: 10
Country: United States
Location: Caladan, Arrakis
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...
__________________

golfzilla is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 12:41 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.