Are classic car mpg ratings accurate?

[AndaBoss]

The thought of asking this is because of the current price of fuel. I have heard from sources online that the Bond Minicar, Reliant Robin and a few other classic cars with small engine capacities have gotten extremely high mpg ratings from 60 to even 100 (some sources below). I've always just assumed modern cars have a high mpg whilst older cars have lower. My parents' Audi A4 1.4 TFSI does 55mpg according to the in-car computer and Audi claims it does 51mpg, which I feel is very economic. I however like shite and classic cars which are known for not being that economic.

Are these claims valid at all, mildly exaggerated or a load of tosh?

 

I'm sure there are people on this forum who have experience with these types of car, so what sort of mpg is actually accurate? Thanks for any help

 

The Bond Minicar Mk A (bondcars.net)

The Bond Minicar Mk C (bondcars.net)

Reliant Robin - Wikipedia

[MJK 24]

I don’t know about the classics but I drove a 1.4 litre 2016 Audi A4 to Italy many moons ago.  Worked out with a pen and paper, it did precisely 49mpg over a few hundred miles thorough France in 34 degree heat with the AC on at 80mph. 

I thought that was super impressive and I look forward to buying one in 2032 when they’re in my price range.

[Stroller133]

My Dad moved on from Robins when I was about 10, so I cant remember/didn't know exact figures, but I'd say his Mk1 Robins would have done more like 50mpg rather than 100mpg. 
Classic Mini 850, 998 or even 1098 engines could all achieve 50mpg driven lightly I'd say. I remember going from Tamworth to Minehead and back a long way round on a really hot summer day and getting around 50+mpg in my Mini Clubman. 

[New POD]

A bloke I worked with at Lucas had done his time and more at "The Austin" in Longbridge. In the engine development section. 

There was manipulation of performance and economy figures, and collusion with car magazines.

They would lend them a car for performance testing, and it woukd be brought back and overnight, a different engine built for economy testing, woukd be fitted. These woukd be built to tolerance, selecting parts off the assembly line and sorting them to give the "right' dimensions.

So theoretically you could get an engine which was at either extreme but highly unlikely. 

That said. I once achieved 45 mpg in an MG metro Turbo on a trip to the lake district. Kept it at dead on 70 mph, where the turbo was just getting started, and the exhaust went a bright white colour on the inside. 

M o st of the time I was getting 25 mpg driving like a rally driver across country to work. 

[Daviemck2006]

I've never really bothered too much over the years of what mpg my vehicles have done. They get ran down to under 1/4 tank then filled up when necessary. The only car I kept a fuel log on was a pug 107 solely used for my work delivering hot food. This was only kept to see if having a car just for that was cost effective. Over something like 26000 miles in a year and a half it averaged 48.5 mpg. I didn't think that was great, but I suppose for the use it got it was ok. I only know that it costs more now to top up than it did. I was in Aberdeen today in the yeti, it was just under 1/2 and I topped up as it's something like 12p a litre cheaper there, and it took £48 to fill it. The trip computer on it says it averages just over 40mpg long term. The caddy doesn't have a mpg computer, I worked out one tank, it was 49 mpg. I do tend to use it more.

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[Mally]

I've had a few Reliant's,  50mpg  is easily achievable.

Bond mini would probably do more on the flat, but are expensive and don't like going up hills.

Minors will do 40's easily.

[sutty2006]

I have successfully achieved 50mpg out of my Opel manta, both with a 2.0 ohc cavalier Sri 130 engine on a 1.8 Weber carb, AND 52mpg with the 2.0 16v Redtop on standard injection. Both runs across France to Holland calculating it properly each fill up. (When your tank sender is faulty and the first 3/4 tank goes in the first 150 miles it’s relatively easy to do haha) 

[artdjones]

I thought I was doing well getting 35mpg out of my 1973 Mini 1000 back in the 80s. I wasn't a particularly hard driver but I suppose a hyper miler would have got 45. 

[AndaBoss]

9 hours ago, MJK 24 said:

I don’t know about the classics but I drove a 1.4 litre 2016 Audi A4 to Italy many moons ago.  Worked out with a pen and paper, it did precisely 49mpg over a few hundred miles thorough France in 34 degree heat with the AC on at 80mph. 

I thought that was super impressive and I look forward to buying one in 2032 when they’re in my price range.

My parents drive this car too and got 55mpg driving at 65-70 on the a12. Well according to the computer 

[Jikovron]

I got a few best i could manage results on some of my past cars showing it to be all over the shop, possibly tune and mileage being a factor, but driving conditions where identical.

91 Metro 1.1 carb : 48mpg 

79 Dolomite 3.5 v8 efi 32mpg 

04 Suzuki ignis 1.3 vvt 53mpg

00 Mk1 focus 2.0 35mpg

78 Skoda estelle 120 carb 36mpg

78 ^^ 1.6 bike carb K-series 30mpg

91 Proton 1300 gls carb 37mpg

91^^ 1.8gti swap 41mpg 

04 Daihatsu charade 1.0 manual 75mpg

04 suzuki alto 1.1 auto 41mpg

94 ford escort 55d van 40mpg

00 fiat seicento 1.1 55mpg

90 merc 300e k jet auto 29mpg

The conclusion was that carbs and/or  bigger engines generally aren't as good.

And in the case of cars from the 50s 60s , low gearing, woeful compression ratios/combustion chambers, aerodynamics and  Clockwork ignition/fueling would waste loads of fuel, hence 1600 Austin Cambridges doing 26mpg etc

 

 

[Toe]

Lightness is a big factor too, and drag, are modern cars worse for that now due to safety?

Anyway before a valve disintegrated (being fixed) my Daihatsu Charade turbo would get around 30mpg around town but have got it up to almost 50 on a motorway early in the morning and at 60, performance biased engine from the factory but still a 1litre. At the time the diesel version claimed to have the best economy of any new car at the time and that was "only" 80mpg odd, so would the 100mpg be pushing it even if they were only plastic so therefore light?

I have fuelly and for the Mazda 323f and Saab 900 Turbo they're both nearly identical, Saab edges it in absolute but not average, 323 around 25mpg over 7,500 miles and Saab at around 22mpg over 9,000 miles but both have hit 36-37mpg on a run, all of them though are under the manufacturer claims of course. 

[wuvvum]

1 hour ago, Jikovron said:

04 Daihatsu charade 1.0 manual 75mpg

04 suzuki alto 1.1 auto 41mpg

The conclusion was that carbs and/or  bigger engines generally aren't as good.

And small engines coupled to automatic gearboxes are thunderously shit - I've struggled to get more than 40mpg on a run out of my 04 Daihatsu Charade 1.0 automatic.  A manual Alto is supposed to do 60-odd as well I think.

[Conan]

Yes, small shite of yesteryears definitely can get 60-100mpg, the real question is at what speed. Can they do that while sustaining 70mph for longer than a few miles? Hell no. Even if they can reach 70 you'd be pressing the go pedal down all the way constantly and the true fuel economy won't be what get advertised.

 

The way to get high fuel economy numbers is to do constant speed that doesn't strain the engine. Less throttle input = better economy. Most moderns, even the cheap and tiny little thing, would be able to do 70 all day while still returning decent fuel economy because they're designed that way. That's what the consumer expects. That's how most people use their cars.

 

From what I've seen, a lot of the old advertisement for little cars usually would cite the consumption rate tested at speed from 30-55mph depending on how ridiculous you want. A modern smol car doing the same speed would return astronomical economy as well, if not better.

[vaughant]

9 hours ago, New POD said:

A bloke I worked with at Lucas had done his time and more at "The Austin" in Longbridge. In the engine development section. 

There was manipulation of performance and economy figures, and collusion with car magazines.

They would lend them a car for performance testing, and it woukd be brought back and overnight, a different engine built for economy testing, woukd be fitted. These woukd be built to tolerance, selecting parts off the assembly line and sorting them to give the "right' dimensions.

So theoretically you could get an engine which was at either extreme but highly unlikely. 

That said. I once achieved 45 mpg in an MG metro Turbo on a trip to the lake district. Kept it at dead on 70 mph, where the turbo was just getting started, and the exhaust went a bright white colour on the inside. 

M o st of the time I was getting 25 mpg driving like a rally driver across country to work. 

A bit like the maestro turbos that could do a 6 second 0-60 because they had the boost wound up to about 25 psi? 

I can remember once if the boys had one and told me it was a "cossie eater" as I owned a cossie at the time. We had a quick race and it couldn't even keep up beyond 20 mpg let alone beyond 70,it looked more like a dot in the mirror at that point yet on paper there was a 1 second to 60 difference. Reality was a very different thing. 

[vaughant]

4 hours ago, sutty2006 said:

I have successfully achieved 50mpg out of my Opel manta, both with a 2.0 ohc cavalier Sri 130 engine on a 1.8 Weber carb, AND 52mpg with the 2.0 16v Redtop on standard injection. Both runs across France to Holland calculating it properly each fill up. (When your tank sender is faulty and the first 3/4 tank goes in the first 150 miles it’s relatively easy to do haha) 

Can only concur on the redtop, mine was breathed on but never dropped below 40mpg in hard driving conditions. 

Peak vauxhall that. 

Did hear the 2.0 8v was just as good. 

I had the same redtop but standard in an Astra gsi and I filled it in Swansea, drive through Wales to alton towers at about 60mph average and it was still on full when I got there!!! 

Drove it to Nottingham the next day and still just off full. 

Got given totally wrong directions to Cadbury world and had to nail it all the way down the M6 toll to catch the last tour and then it did drink a bit.

However being stuck at well over a ton all the way on the private test track that was the m6 toll back in 2006 it was to be expected 🤣🤣. 

[HMC]

I think the technique of the operator has a fair bit to do with the outlying figures, and the conditions.

My personal best mpg as 69mpg out of a bx 1.7td  between Tavistock and Truro over both legs. I Set out with the intention of throwing everything at achieving a good figure- high tyre pressures, hypermiling, coasting where I felt that would work better than the fuel cut off on the overrun (on more gentle inclines I used a combination of the 2) and probably annoyed other road users as well; although a chose what I knew would be a very quiet day. I usually don’t have the patience for it, as using as little fuel as possible in extreme terms takes a lot of concentration and patience.
 

I was alone in the car and it probably would have annoyed passengers as well (most of mine anyway as they tend to be  intent on getting there as fast as possible, which I can also turn my attention to if necessary) 

[warch]

My 60s petrol Landrover does 20-23mpg which isn't much worse than you'd expect from a 2016 transit diesel engined Defender 26-28mpg.

I doubt either of my old Minis 998cc and 1275 (MG Metro engine) ever did more than 40mpg. The smaller engine was underpowered you'd be flat out all the time the bigger one had the Metro diff and 12inch wheels so was very low geared which meant you'd be driving at high rpm at fairly normal road speeds. 

I had a 200 odd horsepower redtop Calibra Turbo, which was about 400kg heavier than the Astra GTE and 4wd, but did have a then very unusual 6 speed gearbox. It reliably did 35-42mpg in normal use, but could absolutely drink petrol flat out. Bear in mind a contemporary Impreza or SX200 would probably struggle to do 30mpg. 

My favourite cars for mpg were a Nova 1.5TD and a Corsa 1.7DTi. The former was a bit slow but neither did less than 55mpg, often more like 70ish, even after I'd remapped the latter to 100hp. A 2.5 straight six diesel automatic Omega could do about 35-40mpg realistically which was acceptable at the time, although it was much better on motorways when the gearbox inefficiency was less of an issue. 

My current car 2007 Nissan Qashqai does 42-mid 50mpg even on shit watered down E10 petrol.  

[RayMK]

I graduated to a brand new 2cv6 in 1975 after my '67 Reliant Regal caught fire and I also sold my motorbike.  The motorbike ('71 CZ175) managed a reasonably consistent 68mpg, ridden at 55-65mph most of the time. The Regal averaged 48mpg and was capable of cruising at 60mph for long distances. At the time, Reliant were advertising the Regal's economy capability as 'up to 101 mpg' courtesy of a rather good result during a Mobil Economy Run.  The 2cv6 was nearly always driven flat out and returned 36mpg, as did a 2nd hand Dyane which I owned in the 1980s.  I have owned a 1961 Reliant Regal MKVI since 1992. It is only capable of 62mph flat out but will cruise at 45-50mph all day, returning around 50mpg. A Rialto which I owned a few years ago was very sprightly, could easily exceed 80mph and generally returned mpg in the high 40s.  I only know one person who has owned a Bond Minicar (type F) and have had a ride in it. 40mph was its typical cruising speed and just over 50mpg was the average. My '94 Fiat Tipo 1.4ie has to be driven extremely gently to achieve 40+mpg. It typically manages 38mpg. So, in line with most of the previous posts, classics of certain types can manage acceptable fuel economy but their lack of engineering sophistication makes them no competition for a modern computer on wheels which will likely have much greater performance while still giving better fuel economy than most classics.

In 1969 I rode my Peugeot BBCT moped, which I'd bought new in Roermond in 1967, all the way back to my Dad's next RAF posting at RAF Nocton Hall, Lincs.   Starting point was RAF Wegberg in Germany and the route in Europe was mainly on cycle tracks to Ostend for the ferry. I did not buy fuel at all on the way as I had a 5litre can strapped on the carrier plus the standard few litres in the main tank. Cruising flat out at 27mph on the flat, it was a long trip. 20mph was more like the journey average and I'd still got stacks of fuel left on arrival in Lincolnshire the next day. It had managed 198mpg. Modern mopeds are nowhere near as frugal 😁. 

[Jikovron]

1 hour ago, wuvvum said:

And small engines coupled to automatic gearboxes are thunderously shit - I've struggled to get more than 40mpg on a run out of my 04 Daihatsu Charade 1.0 automatic.  A manual Alto is supposed to do 60-odd as well I think.

Yeah I found the gearing and convertor slip was disastrous, alto was 15mph per 1000rpm in top when the engine was roughly matched to the box, less when the convertor was allowing some slip where comparitively the charade manual was doing 23mph per 1000 in top and happy to sit at 60 without much effort. Does your auto consequently have the higher tax rate? As our alto was 180quid at the time!

[captain_70s]

I got 35mpg out of my Dolly 1300, driven in a normal manner, 38mpg out of my 1850 driven gently and 24mpg when driven hard. Very dependant on state of tune, neither ventured over 60mph under most scenarios. I usually got better results that period road tests got, but I reckon I drove the cars less hard than the press did on a new motor...

The Acclaim does 35mpg, a long motorway run at a steady 70 will net over 40mpg.

[Zelandeth]

My 81 MiniMetro HLE regularly returned over 50mpg, though we were out in the sticks so things were always going to be pretty favourable.

Averages over how many miles since I started tracking such things, in no particular order.

[] 1991 Skoda 135RiC - 36.2mpg, 1160 miles.

[] 1997 Lada Samara 1.3S - 33.9mpg, 5933 miles.

[] 1988 Skoda 130GL - 38.8mpg, 1498 miles.

[] 1986 Saab 900 5-Speed - 27.1mpg, 5817 miles.

[] 1995 Lada Riva 1.5E Saloon shaped block of rust - 28.2mpg, 605 miles.

[] 2009 Peugeot 107 Verve - 46.7mpg, 52981 miles.

[] 1995 Suzuki Cappuccino - 41.8mpg, 4129 miles.

[] 1996 Lada Niva 1.7i Hussar - 25.4mpg, 9219miles.

[] 1998 Peugeot 306 1.6LX Sedan - 35.1mpg, 3535miles.

-- -- --

It's worth noting that anything past this point is after I moved to Milton Keynes, which is absolute murder on fuel economy as the main road network is a grid of 70mph dual carriageways with a roundabout every 0.9 miles.

-- -- --

[] 1988 Saab 900i Automatic - 22.9mpg, 36531 miles.

[] 1986 Skoda 120LX - 30.7mpg, 2811 miles.

[] 1998 Citroen Xantia 1.9TD - 37.9mpg, 7756 miles.

[] 1995 Lada Riva 1.5i Estate (converted to injection myself) - 23.3mpg, 7116miles.

[] 1990 Mercedes T1 208D AutoTrail Navajo Camper - 24.8mpg, 5429 miles (not tracking currently as actually filling the tank is a massive pain because of a blocked breather).

[] 1973 AC Model-70 - 34.9mpg, 2722 miles.

[] 1985 Jaguar XJ-S V12 HE - 12.8mpg, 5499 miles.

[] 1986 Mercedes S123 230TE - 23.3mpg, 2701 miles.

[] 1996 Citroen Xantia Activa - 22.3mpg, 14550 miles.

[] 2002 VW Caddy 1.9SDI - 44.6mpg, 2553 miles.

[Asimo]

Most oldcar mpg numbers are based on either man-maths or manufacturers wishful thinking so @Zelandeth’s mpg figures are amazing - because they are based on data!

 

[dome]

4 hours ago, vaughant said:

A bit like the maestro turbos that could do a 6 second 0-60 because they had the boost wound up to about 25 psi? 

I can remember once if the boys had one and told me it was a "cossie eater" as I owned a cossie at the time. We had a quick race and it couldn't even keep up beyond 20 mpg let alone beyond 70,it looked more like a dot in the mirror at that point yet on paper there was a 1 second to 60 difference. Reality was a very different thing. 

Slight aside but a chap I used to know many years ago worked at a large motorsport company based near Kendal. His Sapphire Cossie looked standard but certainly wasn't.

A local with a tuned Cossie was constantly pestering him for a race claiming his was the fastest in the area.

They set off one night from a set of lights with the chap I knew at the back.

He ran into the back of the other lads Cossie when they opened them up🤣

[wuvvum]

4 hours ago, Jikovron said:

Does your auto consequently have the higher tax rate? As our alto was 180quid at the time!

Yep, Charade is 155 quid for a year, the manual version is 30.

[MJK 24]

VW Scirocco with 1.6TD - 50.6mpg over 46,000 miles 

Mercedes 124 230E auto - 26.6mpg over 8,000 miles

Meecedes 190 2.5d auto - 38.8mpg over 22,000 miles

Lotus Elise K series - 34mpg over 23,000 miles

[martc]

On 3/20/2022 at 2:57 AM, New POD said:

A bloke I worked with at Lucas had done his time and more at "The Austin" in Longbridge. In the engine development section. 

There was manipulation of performance and economy figures, and collusion with car magazines.

They would lend them a car for performance testing, and it woukd be brought back and overnight, a different engine built for economy testing, woukd be fitted. These woukd be built to tolerance, selecting parts off the assembly line and sorting them to give the "right' dimensions.

So theoretically you could get an engine which was at either extreme but highly unlikely. 

That said. I once achieved 45 mpg in an MG metro Turbo on a trip to the lake district. Kept it at dead on 70 mph, where the turbo was just getting started, and the exhaust went a bright white colour on the inside. 

M o st of the time I was getting 25 mpg driving like a rally driver across country to work. 

[cort1977]

Magazine claims, and even more so manufacturers figures up to diesel gate, are a load of tosh.

I reckon a Citroen AX diesel would be hard to beat for real world, i.e. able to run steadily at 70, fuel economy.

[Liggle]

I've always found Japanese petrol engines to be crap looking on paper MPG wise but closer to reality than anything else, especially Honda and Mazda

[New POD]

1 minute ago, cort1977 said:

 

I reckon a Citroen AX diesel would be hard to beat for real world, i.e. able to run steadily at 70, fuel economy.

I tried comuting from L37 to The Arse end of Burnley in a 1.4D echo.  Every day.  50 mpg was not achievable.  

The fucking thing was so gutless that you had to rag the arse of it.

Not helped by the Hills on the M65. If I wanted to not slow down to 55 mph on the uphill sections, I needed to hit 95 mph on the downhill sections.  

Also not helped by the AX GT wheels and 175 tyres instead of 145. 

[artdjones]

Back in 1990-1 I had a Dolomite 1850 HL I bought at Newport Car Auctions. On the way home it did about 12mpg, but once I advanced the timing it did 24-5 mpg regularly, ok for that size engine, and similar to the 1500 HL I'd had before. 

On a long 75 mph journey with a lot of overdrive use it did 38 mpg, which wouldn't be brilliant for a fairly modern 1.8 car but not disastrous either. You might expect 40-45 mpg. Where fuel economy has really improved is on fairly short journeys, as the cold start enrichment is much more controlled now.