Bongo Fury

I have a four wheel drive Bongo. All the wheels are the same size, I have heard that the rear ones should be different to the front, does anyone know anything about this? It is also only doing about 22 miles to the gallon on a long journey, travelling at about 60/70 mph, any ideas why this is so low?

Hi Rebecca

Many people run Bongo's with the same size tyres all round without a problem. I run different ones front and rear as I think it handles better but each to there own. There's loads of different opinions to be found on here if you do a search for 'tyres'. There's also a factsheet in the members area....so for a few quid you could join and read that.

Fuel consumption....ouch thats low! Bongo's are thirsty but shouldn't be that thirsty.....I get 22-24 around town and I've never got more than 29 on a long run at a constant 65 mph. Some vans will better that.

Firstly, you should check the general service history of your vehicle. If you are unsure of whats been done, you should first change the oil and oil filter as well as the air filter and fuel filter. Also check your tyre pressures.

Does your Bongo perform well and run without odd sounds? Does it produce any smoke? Assuming there is no major engine problem, then a problem with consumption is likely to be down to air or fuel supply issues.

If you supply as much general info about the running of your van to this thread, then you'll likely to be deluged with advice!

Good luck........Rob

Hi Rebecca,

With 4wd the most critical thing with tyres/wheels is that all 4 MUST have the same rolling diameter, or you'll screw up the diffs, transferbox, & gearbox. If your tyres are all the same size, then the rolling diameter is the same so no probs.
HOWEVER - Mazda recommend narrower tyres on the front to aid handling in an emergency (to avoid oversteer on a long, narrow, heavy vehicle). Narrower tyres have to have a different profile to maintain the same rolling diameter.
I've had the same size tyres all around for 2 years with no noticeable handling issues. But I recommend you get a full size spare wheel/tyre if you haven't already. The choice is yours.
As for MPG, that's just a can of worms. Accept that it's a big beast with a fair turn of speed, so it's never going to average much more than your getting now. At a steady 50-55mph it can be quite economical. Mine does 22mpg round town & 22mpg at a steady 85, but 28mpg at 65 fully loaded towing a large trailer. Just ensure the servicing is up to date & enjoy the van.

There's loads more on these 2 subjects if you do a few searches.

The spacesaver is a lot smaller than the standard wheels (diameter I mean) I know that it is only meant for short journey untill you replace the original, but how does that affect the diffs etc on the 4wd

The van is running very well otherwise, I have had the fuel system checked by a garage. It has a new fuel filler and had some fuel cleaner put through the system. It was imported less than a year ago and had a full import service. The next stage recommended is to get a diesel specialist to clean the fuel injectors. Can anyone recommend somewhere to get this done in Sheffield?

I think my tyre pressure is too high, about 40! ...I will sort that (should be 34 rear, 32 front I understand).

Thanks for the advice so far!

If you say your van is running very well then I wouldn't yet go to the expense of touching the injectors. Try the cheap options first. You havn't mentioned if its got a clean air filter. A blocked air filter will raise fuel consumption. Also after a run feel the wheel centres and see if any of them are hot. If so it may be that your brakes are binding which maybe a bit of coppergrease will cure.
Normally if the engine seems to be running well and there is no smoke blowing out of the exhaust when running normally I'd leave it alone.
Over inflation of tyres should not affect fuel consumption but under inflation might.

harpo42 wrote:The spacesaver is a lot smaller than the standard wheels (diameter I mean) I know that it is only meant for short journey untill you replace the original, but how does that affect the diffs etc on the 4wd

I think you will find it is the same diameter. Narrower, sure, but the tyre is the same diameter.

Yes, from memory the space saver was the same diameter as full size, but if it's not kept at maximum pressure (60psi) it's VERY likely that the tyre will come off the rim on the first bend.

so, THIS IS WHY I WOULD RECOMMEND A FULL SIZE SPARE:-

I was at Goodwood a couple of weekends ago with family & friends all in the Freda. We had a brilliant day, but got to the car park, late Saturday evening, ready for a 150 mile 3 hour journey home and FLAT TYRE .
So .... 1/2 hour later with slightly mucky hands, the full size spare was on & off we went without a care in the world. We had a quiet Sunday & I got the punctured tyre repaired on my way home from work on Monday.

Imagine the same scenario with a space saver limited to 50mph & 50 mile maximum range. Taking corners at 20mph, and probably needing to get the AA to take us (& friends) home when the space saver fails. Followed by a miserable Sunday trying to get the puncture repaired, & a new space saver.

& full size spares are 10 a penny due to so many people putting RX8 alloys on their vans.

But, as I said earlier, It's up to you

Also don't forget that many space saver tyres will be maybe 10 years old.

Tyres have a recommended life of six years, so you will be driving on a skinny, potentially perished tyre.

Hi Rebecca, do you leave the aircon on a lot? This can use as much as 15% extra fuel than normal. Try easing the bongo up to speed,and hold as steady a cruise speed as possible... See if that helps