Is Cruise Control More Economical Than A Well Judged Right Foot?

[Konrad C]

Yesterday I went to the Classic Car show at the NEC, and thought the car did reasonably well. It was a mixture if driving with town driving to get across London to the A40 then medium speeds of 50mph then motorway speeds. I used the cruise control going up as there was less traffic on the road and there was no slow traffic. Coming home it was more congested so it was right foot all the way down the M40. Traffic came to a halt a couple of times, but only for a short period. Oh yes it was windy too! Less so coming home. Also when driving normally, I tend to feather the accelerator when cruising in both cars to maintain speed, only using more gas going up hills/inclines. actually both cars add gas when going up hill.

The computer shows just under 36mpg and I had travelled 255 miles. Another thing I notice is the range shows 188 miles.

I have gone beyond the calculated range a few times, and can only fill up with 45 litres. That means I have used 10 gallons and travelled 430 miles. This means the computer is being well reserved, but making the car seem uneconomical compared to my Mk1 which has a good range. Been to the NEC quite a few times and good fuel returns.

The question is how economical cruise control compared to normal right foot?

Another thing is the 2ZR-FAE engine has reasonable torque but the best power is higher up the rev range. The 7A-FE has a peak torque lower down the rev range. Add the extra gear plus the weight, the T27 can feel sluggish in the wrong gear. This is only noticed in certain situations, and they are more rare in todays driving conditions.

[alan333]

You can get better economy than the cruise control can, lift off the gas a bit going uphill and let it roll on down hills. I've had just over 500 miles from mine driving nicely, although my commute to work is quiet roads in the middle of the night and I'm not usually in a hurry.

To do an accurate mpg calculation brim your tank at a garage (on level ground) and set your trip meter miles, then use that tank full, then brim it again (on level ground). See how many litres it takes to fill, divide by 4.54 to convert to gallons, and divide your travelled miles by your gallons. My trip meter is about 5% high, as were two previously owned Toyota autos, but the manual T25 was spot on.

[Cyker]

Until cruise-controls can assess what's in front of the car they'll never be as economical as a good driver; They just lock the car at a certain speed, so if they hit an incline they aren't prepared for it and tend to lose momentum and then waste energy trying to regain it. On a flat they're hard to beat tho' ;)